liven up vs spirit

liven up is not a noun while spirit is a noun.

Word	Noun	Adjective	Verb	Adverb
liven up	No	No	Yes	No
spirit	Yes	No	Yes	No

As verbs, spirit is a hyponym of liven up; that is, spirit is a word with a more specific, narrower meaning than liven up:

Other hyponyms of liven up include ginger up, jazz up, juice up, pep up, inspirit, spirit up.

liven up (noun)	spirit (noun)
	a fundamental emotional and activating principle determining one's character
	animation and energy in action or expression
	an inclination or tendency of a certain kind
	the intended meaning of a communication
	any incorporeal supernatural being that can become visible (or audible) to human beings
	the vital principle or animating force within living things
	the general atmosphere of a place or situation and the effect that it has on people
	the state of a person's emotions (especially with regard to pleasure or dejection)

liven up (verb)	spirit (verb)
make lively	infuse with spirit