[ im-buh-sil, -suh l or, esp. British, -seel ]
/ ˈɪm bə sɪl, -səl or, esp. British, -ˌsil /


Informal. a dunce; blockhead; dolt: Don't stand there like an imbecile. Open the door!.
Psychology. (no longer in technical use; now considered offensive) a person of the second order in a former and discarded classification of mental retardation, above the level of idiocy, having a mental age of seven or eight years and an intelligence quotient of 25 to 50.


Informal. stupid; silly; absurd.
Usually Offensive. showing mental feebleness or incapacity.
Archaic. weak or feeble.



How well do you know your adjectives from your adverbs? Your preposition from your pronouns? Your interjections from your conjunctions? Let’s put your knowledge of parts of speech to the text! Note: Many of the following questions will ask you to identify the parts of speech “in order.” That means the first word in all capital letters will correspond to the first option in an answer, and so on.
Question 1 of 10
In order, what parts of speech are the words in all capital letters? Alisa was VERY tired, SO she decided to go to bed.

Origin of imbecile

1540–50; earlier imbecill < Latin imbēcillus weak; -ile replacing -ill by confusion with suffix -ile


im·be·cil·ic, adjectiveim·be·cile·ly, adverb

Words nearby imbecile Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for imbecile

British Dictionary definitions for imbecile


noun (ˈɪmbɪˌsiːl, -ˌsaɪl)

psychol a person of very low intelligence (IQ of 25 to 50), usually capable only of guarding himself against danger and of performing simple mechanical tasks under supervision
informal an extremely stupid person; dolt

adjective Also: imbecilic (ˌɪmbɪˈsɪlɪk)

of or like an imbecile; mentally deficient; feeble-minded
stupid or senselessan imbecile thing to do

Derived forms of imbecile

imbecilely or imbecilically, adverbimbecility, noun

Word Origin for imbecile

C16: from Latin imbēcillus feeble (physically or mentally)
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

Medical definitions for imbecile

[ ĭmbə-sĭl, -səl ]


A person of moderate to severe mental retardation having a mental age of from three to seven years and generally being capable of some degree of communication and performance of simple tasks under supervision. The term belongs to a classification system no longer in use and is now considered offensive.

Other words from imbecile

imbe•cil′i•ty (-sĭlĭ•tē) n.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.