neck and neck vs nip and tuck

neck and neck is not a noun while nip and tuck is a noun.

Word	Noun	Adjective	Verb	Adverb
neck and neck	No	Yes	No	Yes
nip and tuck	Yes	Yes	No	Yes

As adjectives, neck and neck and nip and tuck are synonyms defined as:

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

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

As adverbs, neck and neck and nip and tuck are synonyms defined as:

neck and neck and nip and tuck: even or close in a race or competition or comparison

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

neck and neck (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

neck and neck (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

neck and neck (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