hold up vs slow down

hold up and slow down both are verbs.

Word	Noun	Adjective	Verb	Adverb
hold up	No	No	Yes	No
slow down	No	No	Yes	No

As verbs, slow down is a hypernym of hold up; that is, slow down is a word with a broader meaning than hold up:

Other hypernyms of hold up include decelerate, retard, slow, slow up.

hold up (verb)	slow down (verb)
cause to be slowed down or delayed	become less tense, rest, or take one's ease
be the physical support of; carry the weight of	lose velocity; move more slowly
hold up something as an example; hold up one's achievements for admiration	become slow or slower
rob at gunpoint or by means of some other threat	reduce the speed of
continue to live and avoid dying	cause to proceed more slowly
resist or withstand wear, criticism, etc.
resist or confront with resistance