unbend vs change state

unbend and change state both are verbs.

Word	Noun	Adjective	Verb	Adverb
unbend	No	No	Yes	No
change state	No	No	Yes	No

As verbs, change state is a hypernym of unbend; that is, change state is a word with a broader meaning than unbend:

Other hypernyms of unbend include turn.

unbend (verb)	change state (verb)
release from mental strain, tension, or formality	undergo a transformation or a change of position or action
become less tense, rest, or take one's ease
make less taut
free from flexure
unfasten, as a sail, from a spar or a stay
straighten up or out; make straight