hold up vs underpin

hold up and underpin both are verbs.

Word	Noun	Adjective	Verb	Adverb
hold up	No	No	Yes	No
underpin	No	No	Yes	No

As verbs, underpin is a hyponym of hold up; that is, underpin is a word with a more specific, narrower meaning than hold up:

Other hyponyms of hold up include scaffold, block, carry, chock, buoy, buoy up, pole, bracket, prop, prop up, shore, shore up, truss, brace.

hold up (verb)	underpin (verb)
cause to be slowed down or delayed	support from beneath
be the physical support of; carry the weight of	support with evidence or authority or make more certain or confirm
hold up something as an example; hold up one's achievements for admiration
rob at gunpoint or by means of some other threat
continue to live and avoid dying
resist or withstand wear, criticism, etc.
resist or confront with resistance