supergrass

British

/ ˈsuːpəˌɡrɑːs /

noun

an informer whose information implicates a large number of people in terrorist activities or other major crimes

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Meanwhile, questions continue to be asked over whether the right men were jailed for the killings, and what happened to the so-called supergrass who turned on them.

From BBC • Dec. 6, 2025

A planned trial collapsed in 2011, after a judge ruled so-called supergrass evidence could not be used in the case.

From BBC • Jun. 18, 2021

Under these terms, he was obliged to confess to everything he had done, and give evidence as a supergrass against any associates facing prosecution.

From The Guardian • Mar. 8, 2018

The lilies and chrysanthemums were far more delicate than the government-enforced supergrass, but at least they were of her choosing.

From Slate • Feb. 21, 2018

Evidence from just one supergrass, Christopher Black, has led to 35 convictions, including that of Kevin Artt.

From Time Magazine Archive

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023