Nearby words

  1. rastaquouere,
  2. raster,
  3. rastle,
  4. rastus,
  5. rasure,
  6. rat cheese,
  7. rat claw foot,
  8. rat fink,
  9. rat guard,
  10. rat islands


    smell a rat, to suspect or surmise treachery; have suspicion: After noting several discrepancies in his client's story, the attorney began to smell a rat.

Origin of rat

before 1000; Middle English rat(t)e, Old English ræt; cognate with Dutch rat, German Ratz, Ratte

Related formsrat·like, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for rat

British Dictionary definitions for rat


/ (ræt) /


verb rats, ratting or ratted

(intr usually foll by on) informal
  1. to divulge secret information (about); betray the trust (of)
  2. to default (on); abandonhe ratted on the project at the last minute
to hunt and kill rats
See also rats

Derived Formsratlike, adjective

Word Origin for rat

Old English rætt; related to Old Saxon ratta, Old High German rato

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

Word Origin and History for rat
Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for rat


[ răt ]


Any of various long-tailed rodents of the genus Rattus and related genera, including certain strains used in scientific research and certain species that are vectors for various diseases.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Idioms and Phrases with rat


In addition to the idioms beginning with rat

  • rat on
  • rat race

also see:

  • like a drowned rat
  • smell a rat
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.