freshen up vs renew

freshen up and renew both are verbs.

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

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

freshen up: make brighter and prettier
renew: reestablish on a new, usually improved, basis or make new or like new

Other hypernyms of freshen up include regenerate.

freshen up (verb)	renew (verb)
become or make oneself fresh again	cause to appear in a new form
make brighter and prettier	reestablish on a new, usually improved, basis or make new or like new