4-0 

Derogatory slang for mall security guards/vehicles. Derived from 5-0, a slang term for police officers/vehicles.

The 4-0 got on my ass after I boosted that Clay Aiken CD from Sam Goody.

4-0 by Sam March 4, 2004

4-0 

Often used by fans of finished club FC Barcelona when something doesn’t go their way and they get mad. Their biggest trophy and achievement in season 2021/2022. Used by them to annoy other people but they didn’t found out yet that nobody cares anymore.

Person 1: Real Madrid are winning La Liga this season, maybe UCL and will get Mbappe for free.
Person 2: 4-0.

4-0 by honest barcelona fan April 9, 2022

4-0 

A civilian or any non-law enforcement person who will (try to) bust you.

You check for people in here, I'm not tryna get caught

Yeah, no 4-0, were good.

4-0 by pitabreadyum July 6, 2010

4-0 

Street slang for an undercover cop.

Ay mane I think a 4-0 dry dat vic mane

4-0 by Champ119 August 4, 2017

4-0 

slang for a fourdypronunced four-o.

He the the store and get me a 4-0.

4-0 by B from the bay December 23, 2005

4-0 

The answer for when somebody says "thank you" by typing "10x"
4-0 means "for nothing" as in "think nothing of it", "you're welcome", "don't mention it", "no problem" etc

A: 10x for helping me the other day
B: 4-0

4-0 by Satyga October 17, 2017

₄-⁰ 

a gay man who is into old femboy grandpas on twitter

goo goo gaa gaa im like ₄-⁰ i like femboys waaa uWu

₄-⁰ by lebron jahamez April 26, 2022