(1):

(v. t.) To emasculate; to deprive of virility.

(2):

(v. t.) To deprive of the courage and fortitude of a man; to break or subdue the manly spirit in; to cause to despond; to dishearten; to make womanish.

(3):

(v. t.) To deprive of the distinctive qualities of a human being, as reason, or the like.

(4):

(v. t.) To deprive of men; as, to unman a ship.