Imbecile a. : Destitute of strength, whether of body or mind; feeble; impotent; esp., mentally wea; feeble-minded; as, hospitals for the imbecile and insane.

Imbecile n. : One destitute of strength; esp., one of feeble mind.

Imbecile v. t. : To weaken; to make imbecile; as, to imbecile men's courage.

Example:
Is it an insult to be called an Imbecile?

Taxonomy
imbecile, idiot, Dictionary, acumen, fool, Synonyms, Antonyms, 能者, Houghton Mifflin Company, silly person, dolt, severe mental retardation, Thesaurus, genius, Translations, cile, Literature & Language, jackass.

Defination from the web:
imbecile n. A stupid or silly person; a dolt. A person whose mental acumen is well below par. A person of moderate to severe mental retardation ... How hard it is to make your thoughts look anything but imbecile fools when you paint them with ink on paper. — Olive Schreiner (1855 ...