wash up vs freshen up

wash up and freshen up both are verbs.

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

As verbs, freshen up is a hypernym of wash up; that is, freshen up is a word with a broader meaning than wash up:

Other hypernyms of wash up include freshen, refresh, refreshen.

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