Emily Dickinson Lexicon

BAT-TAL'ION, n. [Fr. bataillon. See Battle.]

A body of infantry, consisting of from 500 to 800 men; so called from being originally a body of men arrayed for battle. A battalion is generally a body of troops next below a regiment. Sometimes a battalion composes a regiment; more generally a regiment consists of two or more battalions. – Johnson. Encyc. Shakspeare uses the word for an army.