battalion vs large number

battalion and large number both are nouns.

Word	Noun	Adjective	Verb	Adverb
battalion	Yes	No	No	No
large number	Yes	No	No	No

As nouns, battalion and large number are synonyms defined as:

Other synonyms of battalion include multitude, pack, plurality.

battalion (noun)	large number (noun)
an army unit usually consisting of a headquarters and three or more companies	a large indefinite quantity
a large indefinite quantity