Etymology: < (i) Middle French, French †imbecille, French imbécile physically weak (1496), lacking intellect (1509), morally weak (1541), or its etymon (ii) classical Latin imbēcillus, imbēcillis weak, feeble, delicate, fragile, ineffective, lacking intellectual or moral strength; of unknown origin.Compare Spanish imbécil (1524), Portuguese imbecil (1589), Italian imbecille (early 14th cent.). Specific senses. In sense A. 2 after embezzle v. Historical variation in spelling and pronunciation. The spelling imbecile , already attested in the 17th cent., became established in the 18th cent. and is based on an erroneous impression that the form of the classical Latin word was imbecilis (so stated in Bailey's Folio, repeated by Johnson, and made the basis of argument by Walker). The pronunciation /ɪmˈbɛsɪl/, connected with the confusion of this word and embezzle v., was usual until the beginning of the 19th cent., and was preferred by Walker (1791), although the pronunciation /ɪmbɪˈsiːl/ (after French imbécille) is said to have been ‘the more fashionable’ ( J. Walker Crit. Pronouncing Dict. at imbecile).

Etymology: < imbecile adj. Compare earlier embezzle v.Compare post-classical Latin imbecillare to weaken (from 12th cent. in British sources).