relax vs slow down

relax and slow down both are verbs.

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

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

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

relax (verb)	slow down (verb)
become less tense, rest, or take one's ease	become less tense, rest, or take one's ease
cause to feel relaxed	lose velocity; move more slowly
make less taut	become slow or slower
become loose or looser or less tight	reduce the speed of
make less active or fast	cause to proceed more slowly
become less severe or strict
make less severe or strict
become less tense, less formal, or less restrained, and assume a friendlier manner