Definition from Wiktionary, the free dictionary
From French bataillon.
battalion (plural battalions)
- (military) An army unit having two or more companies, etc. and a headquarters. Traditionally forming part of a regiment.
- (US, military) an army unit having two or more companies, etc. and a headquarters; forming part of a brigade.
- Any large body of troops.
- (by extension) A great number of things.
any large body of troops
- To form into battalions.