straighten out vs amend

straighten out and amend both are verbs.

Word	Noun	Adjective	Verb	Adverb
straighten out	No	No	Yes	No
amend	No	No	Yes	No

As verbs, amend is a hypernym of straighten out; that is, amend is a word with a broader meaning than straighten out:

Other hypernyms of straighten out include ameliorate, better, improve, meliorate.

straighten out (verb)	amend (verb)
put (things or places) in order	to make better
settle or put right	set straight or right
change for the better	make amendments to
make free from confusion or ambiguity; make clear
make straight
extricate from entanglement