war machine vs battle

war machine and battle both are nouns.

Word	Noun	Adjective	Verb	Adverb
war machine	Yes	No	No	No
battle	Yes	No	Yes	No

war machine (noun)	battle (noun)
the military forces of a nation	a hostile meeting of opposing military forces in the course of a war
	an energetic attempt to achieve something
	an open clash between two opposing groups (or individuals)

war machine (verb)	battle (verb)
	battle or contend against in or as if in a battle