unbend vs slow down

unbend and slow down both are verbs.

Word	Noun	Adjective	Verb	Adverb
unbend	No	No	Yes	No
slow down	No	No	Yes	No

As verbs, unbend and slow down are synonyms defined as:

Other synonyms of unbend include decompress, loosen up, relax, unwind.

unbend (verb)	slow down (verb)
release from mental strain, tension, or formality	become less tense, rest, or take one's ease
become less tense, rest, or take one's ease	lose velocity; move more slowly
make less taut	become slow or slower
free from flexure	reduce the speed of
unfasten, as a sail, from a spar or a stay	cause to proceed more slowly
straighten up or out; make straight