flatten vs modify

flatten and modify both are verbs.

Word	Noun	Adjective	Verb	Adverb
flatten	No	No	Yes	No
modify	No	No	Yes	No

As verbs, modify is a hypernym of flatten; that is, modify is a word with a broader meaning than flatten:

Other hypernyms of flatten include alter, change.

flatten (verb)	modify (verb)
become flat or flatter	make less severe or harsh or extreme
make flat or flatter	add a modifier to a constituent
lower the pitch of (musical notes)	cause to change; make different; cause a transformation