(1):

(n.) One destitute of strength; esp., one of feeble mind.

(2):

(v. t.) To weaken; to make imbecile; as, to imbecile men's courage.

(3):

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