head-to-head vs nip and tuck

head-to-head is not a noun while nip and tuck is a noun.

Word	Noun	Adjective	Verb	Adverb
head-to-head	No	Yes	No	Yes
nip and tuck	Yes	Yes	No	Yes

As adjectives, head-to-head and nip and tuck are synonyms defined as:

head-to-head and nip and tuck: inconclusive as to outcome; close or just even in a race or comparison or competition

Other synonyms of head-to-head include neck and neck.

As adverbs, head-to-head and nip and tuck are synonyms defined as:

head-to-head and nip and tuck: even or close in a race or competition or comparison

Other synonyms of head-to-head include neck and neck.

head-to-head (noun)	nip and tuck (noun)
	plastic surgery to remove wrinkles and other signs of aging from your face; an incision is made near the hair line and skin is pulled back and excess tissue is excised

head-to-head (adjective)	nip and tuck (adjective)
inconclusive as to outcome; close or just even in a race or comparison or competition	inconclusive as to outcome; close or just even in a race or comparison or competition
involving two persons; intimately private

head-to-head (adverb)	nip and tuck (adverb)
even or close in a race or competition or comparison	even or close in a race or competition or comparison