supergrass
In real, traceable use. Part of the curated seed collection; community review is coming.
Meaning · English
An informer providing substantial quantities of information on criminal or terrorist activities to the police.
Register: slang
Examples
I have to tell the hon. and learned Gentleman that I do not know the facts which led to that decision. On the other hand, although it is an unpleasant fact of life, there are now and again occasions on which, in order to achieve convictions against really bad villains, it is necessary to use people
Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30)
Sources & notes
Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30 via kaikki.org).
Common questions
What does “supergrass” mean?
An informer providing substantial quantities of information on criminal or terrorist activities to the police.
Is “supergrass” formal or informal?
supergrass is generally slang.