let up vs alter

let up and alter both are verbs.

Word	Noun	Adjective	Verb	Adverb
let up	No	No	Yes	No
alter	No	No	Yes	No

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

Other hypernyms of let up include change, modify.

let up (verb)	alter (verb)
become less in amount or intensity	remove the ovaries of
reduce pressure or intensity	become different in some particular way, without permanently losing one's or its former characteristics or essence
	cause to change; make different; cause a transformation
	insert words into texts, often falsifying it thereby
	make an alteration to