(1):

(n.) A body of troops; esp. a body of troops or an army in battle array.

(2):

(n.) A regiment, or two or more companies of a regiment, esp. when assembled for drill or battle.

(3):

(v. t.) To form into battalions.

(4):

(n.) An infantry command of two or more companies, which is the tactical unit of the infantry, or the smallest command which is self-supporting upon the battlefield, and also the unit in which the strength of the infantry of an army is expressed.