take the field vs war

take the field is not a noun while war is a noun.

Word	Noun	Adjective	Verb	Adverb
take the field	No	No	Yes	No
war	Yes	No	Yes	No

take the field (noun)	war (noun)
	the waging of armed conflict against an enemy
	a concerted campaign to end something that is injurious
	an active struggle between competing entities
	a legal state created by a declaration of war and ended by official declaration during which the international rules of war apply

take the field (verb)	war (verb)
go on the playing field, of a football team	make or wage war
go on a campaign; go off to war