head-to-head vs private

head-to-head is not a noun while private is a noun.

Word	Noun	Adjective	Verb	Adverb
head-to-head	No	Yes	No	Yes
private	Yes	Yes	No	No

head-to-head (noun)	private (noun)
	an enlisted man of the lowest rank in the Army or Marines

head-to-head (adjective)	private (adjective)
inconclusive as to outcome; close or just even in a race or comparison or competition	confined to particular persons or groups or providing privacy
involving two persons; intimately private	not expressed
	concerning one person exclusively
	concerning things deeply private and personal

head-to-head (adverb)	private (adverb)
even or close in a race or competition or comparison