How do you spell Imbecile

Available Definitions:
1)  a. - Destitute of strength, whether of body or mind; feeble; impotent; esp., mentally wea; feeble-minded; as, hospitals for the imbecile and insane.
2)  n. - One destitute of strength; esp., one of feeble mind.
3)  v. t. - To weaken; to make imbecile; as, to imbecile men's courage.