rat
- 01 A2 Elementary
n.a small animal with a long tail that looks like a large mouse.
n.any of various medium-sized rodents, particularly those in the genus Rattus, characterized by a long hairless tail and a pointed snout.
Simple“The old warehouse was full of rats looking for food in the rubbish.”
In context“Urban planners must account for the resilience of rat populations when designing waste management systems for densely populated city centres.”
Synonyms - 02 B2 Upper Intermediate
n.a person who is dishonest or betrays their friends or group.
n.a person who betrays a person, group, or cause; often used for an informant who gives information to the police.
Simple“He called his former partner a rat for telling the boss about the mistake.”
In context“In many underworld narratives, the character identified as the rat often faces severe consequences for violating the code of silence.”
- 03 B2 Upper Intermediate
v.to tell the police or someone in power about something bad another person did.
v.to inform on someone or betray a secret to the authorities; often used with the preposition 'on'.
Simple“He decided to rat on his friends to avoid going to jail.”
In context“The witness was hesitant to rat on the gang members, fearing that the police could not provide adequate protection after the trial.”
UsageUsually takes the preposition 'on'.
- 04 C1 Advanced
v.to leave a group or a political party when they are in trouble.
v.to desert or betray a political party, cause, or principle, especially for personal gain.
Simple“Several members of the party chose to rat when the scandal became public.”
In context“The prime minister accused the defectors of ratting on the administration during its most vulnerable hour.”
“To investigate whether curcumin could reduce this damage, researchers used a rat model of Type 1 diabetes.”
“In a 2024 study , her team tested this possibility in groups of female rats.”
From Middle English ratte, rat, rotte, from Old English rætt, from Proto-West Germanic ratt, from Proto-Germanic rattaz, rattō (compare West Frisian rôt, Dutch rat), of uncertain origin, possibly from Proto-Indo-European Hreh₃d- (“to scrape, scratch, gnaw”). However, the rat may have been unknown in Northern Europe in antiquity, and the Proto-Germanic word may have referred to a different animal; see *rattaz for more. Attestation of this family of words begins in the 12th century. Some of the Germanic cognates show considerable consonant variation, e.g. Middle Low German ratte, radde; Middle High German rate, ratte, ratze. The irregularity may be symptomatic of a late dispersal of the word, although Kroonen accounts for it with a Proto-Germanic stem raþō nom., ruttaz gen., showing both ablaut and a Kluge's law alternation, with the variation arising from varying remodellings in the descendants. Kroonen states that this requires a Proto-Indo-European etymon in final t and is incompatible with the usual derivation from Proto-Indo-European Hreh₃d- (“to scrape, scratch, gnaw”).
From Middle English ratten, further etymology unknown. Compare Middle Low German retten (“to tear, tear up”), Middle High German ratzen (“to scratch; rasp; tear”). Could be related to write. See also rit.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.