slow down vs unwind

slow down and unwind both are verbs.

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

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

Other synonyms of slow down include decompress, loosen up, relax, unbend.

slow down (verb)	unwind (verb)
become less tense, rest, or take one's ease	become less tense, rest, or take one's ease
lose velocity; move more slowly	cause to feel relaxed
become slow or slower	separate the tangles of
reduce the speed of	reverse the winding or twisting of
cause to proceed more slowly