Grass British Slang Snitch, Informant & More in 2026

“Grass” is British slang for someone who informs on another person, usually to the police. Calling someone a “grass” means they snitched or told on someone else. The term can also work as a verb, as in “to grass someone up.” It’s one of the most common insults in British English for a snitch.

Key Takeaways

• “Grass” means an informant, snitch, or someone who tells on others
• It can be used as a noun (“he’s a grass”) or a verb (“don’t grass me up”)
• The term likely comes from Cockney rhyming slang, though the exact path is debated
• It’s been in common use since at least the mid-1900s
• The tone is almost always negative, sometimes seriously so in criminal contexts
• Still widely used today across the UK in everyday speech, TV, and online

If you’ve watched a British crime show, listened to UK drill or grime music, or scrolled through comments from British users online, you’ve probably run into the word “grass.” People search this term because it shows up in dialogue without any explanation, and it doesn’t sound like it means what it means. A patch of grass and a person who snitches share nothing in common on the surface, so the confusion is fair.

This word is still very much alive in the UK today. You’ll hear it in pubs, schools, prisons, football stadiums, and police dramas. It carries weight because snitching is treated as a serious social offense in many British communities, especially in working-class and criminal circles. Calling someone a grass british slang term isn’t just teasing. It can end friendships or worse.

This guide covers everything you need to know: what grass means, where it likely came from, how it’s used now, and the many related terms and phrases built around it. By the end, you’ll understand every version of the word, from “grassed up” to “no grass rule,” and you’ll know exactly when it’s safe or unsafe to use it yourself.

What Does Grass British Slang Mean?

In short, a “grass” is a person who informs on someone else, most often to the police or an authority figure. The word can describe the person or the act itself.

There are a few common ways it shows up:

• Noun: “He’s a grass” means he’s an informant or snitch.
• Verb: “Don’t grass on me” means don’t tell on me or report me.
• Phrase: “Grass someone up” means to report or expose them, usually to get them in trouble.

Example: “The whole estate found out he was a grass after he talked to the cops.”

This meaning is consistent across most of the UK, though the intensity of the insult can shift depending on context. In a school setting, being called a grass might just mean you told a teacher something. In criminal or gang contexts, it’s a far more serious accusation tied to loyalty and trust.

Quick Meaning Box

Meaning	Simple Explanation
Grass (noun)	A person who informs on someone, a snitch
Grass (verb)	To tell on or report someone
Grass up	To expose or report someone, often to police
Grassed	Past tense — already told on someone
Grasser	Another word for an informant

Pronunciation

“Grass” is pronounced just like the plant: /ɡrɑːs/ in standard British English, or /ɡræs/ in American English. There’s no special pronunciation twist here. The slang meaning is understood entirely from context, not from how the word sounds.

Where Does Grass British Slang Come From?

The most widely accepted theory is that “grass” comes from Cockney rhyming slang, specifically “grasshopper,” which rhymes with “copper” (a slang term for police officer). Over time, “grasshopper” may have been shortened to “grass,” and the meaning shifted from referring to the police themselves to referring to someone who talks to the police.

The exact origin is unclear, and language historians don’t all agree on a single clean explanation. Some sources connect the term to older British criminal slang from the early to mid-20th century, where informants were already being described using plant or nature-related euphemisms. What’s clear is that by the mid-1900s, “grass” was firmly established in British underworld and working-class vocabulary as a word for an informant.

History of the Term

“Grass” has stuck around for decades without much change in meaning, which is unusual for slang. Most slang terms fade or shift meaning within a generation. This one hasn’t.

Through the 1900s, the word was closely tied to criminal culture, prisons, and police dealings. It described people who broke the unwritten code of silence, whether that was among criminals, gang members, or just neighbors who didn’t want the police involved in local matters.

By the late 20th century, “grass” had spread well beyond criminal circles into everyday British English. Schoolkids used it for classmates who told teachers on them. Football fans used it for players who complained to referees. It became a general-purpose word for tattling, not just serious criminal informing.

In recent years, UK drill and grime music have kept the term visible to younger audiences, often referencing the seriousness of “grassing” and the social consequences that come with it. This has helped the word stay current rather than sounding old-fashioned.

How People Use It Today

Today, “grass” appears across British TV crime dramas, music lyrics, football commentary, and everyday conversation. On social media, British users use it in comment sections and captions, especially on X and TikTok, when discussing news stories involving informants or people exposing others.

It’s less common on American platforms simply because the word isn’t part of standard American slang, but British creators and commenters use it freely and expect their audience to understand it. It shows up in texting between British friends just as often as in speech.

Grass British Slang Origin

The origin traces back most convincingly to Cockney rhyming slang, where “grasshopper” stood in for “copper” (police officer). Some researchers also link it to older prison slang.

Beyond the rhyming slang theory, there’s a secondary idea floating around that “grass” relates to “snake in the grass,” an old English idiom for a hidden, untrustworthy person. This idiom predates the slang use and may have reinforced the word’s negative meaning even if it wasn’t the direct source. Because no single document confirms one origin story over the other, it’s fairest to say the exact origin is unclear, but the rhyming slang connection is the most commonly cited explanation.

Top Grass British Slang Terms to Know

Beyond the basic word “grass,” British English has built a small family of related terms around it. Knowing these helps you understand conversations, headlines, and lyrics without getting lost.

• Grass – an informant
• Grass up – to inform on someone
• Grassed – past tense, already informed
• Grasser – another word for a snitch
• Supergrass – a high-profile informant, often one who testifies against former criminal associates in a major case

“Supergrass” is worth knowing on its own, since it’s commonly used in UK news coverage of criminal trials.

British Slang Grass You Up

“Grass you up” means to report you or expose your wrongdoing to someone in authority, usually without warning. It’s used as a threat or an accusation.

Example: “If you try anything, I’ll grass you up to the manager.”

This phrase carries a sense of betrayal. It’s not neutral reporting; it implies breaking trust or loyalty to get someone else in trouble.

No Grass Rule British Slang

The “no grass rule” refers to an unwritten code, especially strong in criminal and gang culture, that says you never inform on someone else no matter what happens. Breaking this rule is considered one of the worst things a person can do in these circles.

This rule isn’t official or written down anywhere. It’s a social expectation passed through communities, prisons, and criminal networks. Someone who breaks it risks serious social or physical consequences, which is part of why the word “grass” carries so much weight compared to a milder word like “tattletale.”

British Slang Calling Someone a Grass

Calling someone a grass is a direct accusation that they informed on someone else. It’s rarely said lightly in serious contexts, though it can be used more casually among friends or kids.

In a joking context between mates, it might mean nothing more than “you told on me for something small.” In a more serious context, especially involving police, gangs, or criminal matters, calling someone a grass can damage reputations and relationships permanently.

British Mob Slang Grass

Within British criminal and mob-adjacent culture, “grass” is one of the most feared labels a person can receive. Informing on associates to police is treated as a betrayal of loyalty, and the word carries real social danger in these circles.

This is where “supergrass” also comes from, referring to informants who provide testimony that leads to multiple convictions. These cases often get major news coverage in the UK because of how much they can disrupt organized crime networks.

Grassed Up British Slang

“Grassed up” is the past tense form, describing something that already happened. “He grassed me up to the boss” means he already reported you.

This form is common in storytelling and complaints. People use it when explaining how they got caught or how someone else was exposed after the fact.

Grasser British Slang

“Grasser” is simply another noun for an informant, functioning the same way as “grass” itself. Some regions and speakers prefer “grasser” as a slightly more casual or old-fashioned variant.

You’ll hear both used interchangeably, though “grass” is far more common in modern speech and writing.

Grasshopper British Slang

“Grasshopper” is the full rhyming slang term believed to be the origin of “grass” as slang for an informant, since it rhymes with “copper” (police officer). Over time, people shortened “grasshopper” to just “grass,” and the meaning shifted from the police to the person telling the police.

Outside of this slang history, “grasshopper” doesn’t carry the informant meaning on its own in everyday British speech today. It’s mostly relevant as background for understanding where “grass” came from.

What Does Grassing Mean in British Slang?

“Grassing” is the ongoing or general act of informing on someone, used as a gerund. “He’s always grassing on people” describes a pattern of behavior, not a single event.

This form is used to describe someone’s character or habits, not just a one-time action. Someone labeled as “always grassing” has a reputation for being untrustworthy with information.

Examples in Everyday Conversation

• “Don’t tell him anything, he’s a known grass.”
• “She grassed me up for skipping class.”
• “Nobody trusts him since he grassed on his mates.”
• “If you grass me up, we’re done as friends.”
• “The whole team knows he’s a grass now.”
• “I heard he grassed to get a lighter sentence.”
• “She’s not a grass, she just told the truth.”
• “He got labeled a grass after one conversation.”
• “Don’t be a grass, just let it go.”
• “They say he grassed up his own brother.”

Text Message Examples

• “lol did u really grass me up to mum??”
• “he’s such a grass, told the teacher everything”
• “don’t grass ok just keep it between us”
• “heard she grassed on the whole group chat”
• “im not a grass i just answered a question”
• “he grassed himself up basically, kept talking”
• “why would you grass over something so small”
• “she’s known as a grass at school now”
• “nobody likes a grass, keep quiet”
• “nah he wouldn’t grass, he’s solid”

Social Media Caption Examples

• Instagram: “Loyalty over everything, never been a grass 🙅‍♂️”
• TikTok: “POV you got grassed up by your own group chat”
• X/Twitter: “The supergrass trial is wild, can’t believe he flipped”
• Threads: “Why do people act shocked when a grass gets exposed?”
• Facebook: “Reminder: snitches and grasses never end up looking good”
• Instagram: “Grass season is over, keep your business to yourself”
• TikTok: “When your best mate turns out to be a grass 💀”
• X/Twitter: “British slang lesson: grass = snitch, you’re welcome”
• Threads: “Not me getting grassed up over something so small”
• Facebook: “Some people will grass on you for nothing, be careful”

Is Grass Positive or Negative?

“Grass” is almost always negative. It’s an insult that accuses someone of betrayal, disloyalty, or breaking trust by informing on others.

There are rare cases where the underlying action (reporting real wrongdoing) might be seen as justified, but the word itself still carries a negative charge. Saying “he’s a grass” is never a compliment, even if the person had good reasons for speaking up. The main risk of misunderstanding comes from outsiders who don’t realize how serious the accusation can feel in British contexts, especially compared to a lighter word like “tattletale.”

Who Uses This Slang?

“Grass” is used across a wide range of ages and groups in the UK. Teens use it in schools, adults use it in workplaces and social settings, and it’s especially common in discussions of crime, football, and prison culture. It also shows up regularly in UK drill and grime lyrics, and in British crime dramas and tabloid news coverage of criminal trials.

It’s not tied to one single generation. Older British speakers grew up with the word, and younger speakers keep it alive through music and social media.

Similar Slang Words

Slang	Meaning
Snitch	American English term for an informant
Rat	Informal term for someone who informs, common in both US and UK
Supergrass	A high-profile British informant in major criminal cases
Nark	Older British slang for an informant, especially to police
Tout	Northern Irish and Irish term for an informant

Opposite Words

• Loyal – someone who keeps information private and stands by others
• Solid – British slang for someone trustworthy who won’t inform
• Ride or die – someone unconditionally loyal, regardless of consequences
• Tight-lipped – someone who doesn’t share information easily

Common Mistakes

People sometimes confuse “grass” the slang term with “grass” the plant, especially in translated or auto-generated content that misreads context. Others assume it only relates to marijuana slang, which is a completely separate and unrelated use of the word “grass” in American slang. In British contexts, the informant meaning is by far the most common, especially in crime, sports, and everyday conversation. Another mistake is treating “grass” as a light or playful word in every situation. In serious contexts, it can be a heavy accusation, not just casual teasing.

When NOT to Use It

Avoid using “grass” in professional emails, school assignments, job interviews, or formal writing. It’s slang tied closely to informal and sometimes criminal contexts, so it doesn’t fit workplaces, customer service, or academic settings.

It’s also risky to use casually around people you don’t know well, since accusing someone of being a grass can be taken as a serious insult rather than a joke. When in doubt, stick to neutral words like “informant” or “reported” in formal situations.

Fun Facts

• “Grass” likely comes from Cockney rhyming slang: “grasshopper” rhymes with “copper” (police).
• “Supergrass” is used specifically for major informants in high-profile UK criminal cases.
• The word has stayed largely unchanged in meaning for decades, unlike many slang terms.
• It’s common in UK drill and grime music lyrics today.
• British football fans sometimes use it jokingly for players who complain to referees.
• The word doesn’t carry the same weight in American English, where “snitch” is more common.

Frequently Asked Questions

Why do Brits call informants grass? 

The most accepted explanation ties back to Cockney rhyming slang, where “grasshopper” rhymed with “copper,” a term for police. Over time, people shortened “grasshopper” to “grass,” and the meaning shifted from describing police to describing the person who talks to them. The exact origin is unclear, since language historians don’t have one confirmed written source, but this rhyming slang path is the most commonly cited theory across British language references.

What is British slang for a hot girl? 

British slang for an attractive woman includes words like “fit,” “peng,” and “bird” (though “bird” is more general slang for a woman, not specifically about looks). “Fit” is one of the most common, used the same way Americans might say someone is “hot.” These terms are casual and used mostly among younger speakers or in informal settings.

What is sod in British slang? 

“Sod” is a mild British insult, often used affectionately or in frustration, similar to calling someone a “pain” or a “nuisance.” It comes from “sodomite,” though modern use has softened it into a general, mild term of annoyance, like “you cheeky sod” or “poor sod” for someone unlucky.

What is the British word for “snitch”? 

The main British equivalent is “grass,” though “nark” is also used, especially by older speakers, and “supergrass” applies specifically to major informants in criminal cases. “Grass” remains the most widely recognized and commonly used version across the UK today.

What is the Irish word for “snitch”? 

In Ireland, “tout” is a commonly used word for an informant, particularly in Northern Ireland, where it has historical weight tied to conflict-era informing. “Grass” is also understood and used in Ireland due to shared British media and culture, but “tout” carries a distinctly Irish identity.

What is the word for someone who tells on another person? 

Common words include “snitch,” “tattletale,” “informant,” “rat,” and in British English specifically, “grass.” Each word carries a slightly different tone: “tattletale” sounds childish and mild, while “grass” and “informant” can apply to serious adult situations, including criminal cases.

Final Thoughts

“Grass” is one of those British slang words that sounds harmless until you understand what it actually means. Once you know it points to informants and snitches, entire conversations, song lyrics, and crime shows suddenly make a lot more sense. It’s not a trendy new term either. It’s been around for generations and shows no sign of fading from everyday British English.

Whether you’re trying to understand a British friend’s texts, follow along with UK drama, or just build your slang vocabulary, “grass” is worth knowing well. Just remember the tone: it’s rarely playful, and calling someone a grass is an accusation people take seriously across the UK.