freshen vs alter

freshen and alter both are verbs.

Word	Noun	Adjective	Verb	Adverb
freshen	No	No	Yes	No
alter	No	No	Yes	No

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

Other hypernyms of freshen include change, modify.

freshen (verb)	alter (verb)
make fresh again	remove the ovaries of
become or make oneself fresh again	become different in some particular way, without permanently losing one's or its former characteristics or essence
make (to feel) fresh	cause to change; make different; cause a transformation
	insert words into texts, often falsifying it thereby
	make an alteration to