undo vs alter

undo and alter both are verbs.

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

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

Other hypernyms of undo include change, modify.

undo (verb)	alter (verb)
cancel, annul, or reverse an action or its effect	remove the ovaries of
cause to become loose	become different in some particular way, without permanently losing one's or its former characteristics or essence
remove the outer cover or wrapping of	cause to change; make different; cause a transformation
deprive of certain characteristics	insert words into texts, often falsifying it thereby
cause the ruin or downfall of	make an alteration to