soak up vs suck

soak up is not a noun while suck is a noun.

Word	Noun	Adjective	Verb	Adverb
soak up	No	No	Yes	No
suck	Yes	No	Yes	No

As verbs, soak up and suck are synonyms defined as:

Other synonyms of soak up include absorb, draw, imbibe, sop up, suck up, take in, take up.

soak up (noun)	suck (noun)
	the act of sucking

soak up (verb)	suck (verb)
devote (oneself) fully to	give suck to
take in, also metaphorically	draw into the mouth by creating a practical vacuum in the mouth
	take in, also metaphorically
	draw something in by or as if by a vacuum
	provide sexual gratification through oral stimulation
	be inadequate or objectionable
	attract by using an inexorable force, inducement, etc.