freshen up vs wash up

freshen up and wash up both are verbs.

Word	Noun	Adjective	Verb	Adverb
freshen up	No	No	Yes	No
wash up	No	No	Yes	No

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

Other hyponyms of freshen up include lave.

freshen up (verb)	wash up (verb)
become or make oneself fresh again	wash one's face and hands
make brighter and prettier	wear out completely
	be carried somewhere by water or as if by water
	wash dishes
	carry somewhere (of water or current or waves)