decelerate vs slow down

decelerate and slow down both are verbs.

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

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

Other synonyms of decelerate include retard, slow, slow up.

As verbs, slow down is a hyponym of decelerate; that is, slow down is a word with a more specific, narrower meaning than decelerate:

Other hyponyms of decelerate include slow, slow up, delay, detain, hold up.

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

decelerate (verb)	slow down (verb)
lose velocity; move more slowly	become less tense, rest, or take one's ease
reduce the speed of	lose velocity; move more slowly
	become slow or slower
	reduce the speed of
	cause to proceed more slowly