(1):

(n.) Barley or other grain, steeped in water and dried in a kiln, thus forcing germination until the saccharine principle has been evolved. It is used in brewing and in the distillation of whisky.

(2):

(v. t.) To make into malt; as, to malt barley.

(3):

(a.) Relating to, containing, or made with, malt.

(4):

(v. i.) To become malt; also, to make grain into malt.