absorb vs mop up

absorb is not a noun while mop up is a noun.

Word	Noun	Adjective	Verb	Adverb
absorb	No	No	Yes	No
mop up	Yes	No	Yes	No

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

Other hyponyms of absorb include mop, wipe up, blot, sponge up.

absorb (noun)	mop up (noun)
	a concluding action

absorb (verb)	mop up (verb)
cause to become one with	finish a task completely
take up mentally	defeat thoroughly
consume all of one's attention or time	to wash or wipe with or as if with a mop
devote (oneself) fully to
take in, also metaphorically
become imbued
assimilate or take in
take up, as of debts or payments
suck or take up or in