mop vs mop up

mop and mop up both are nouns.

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

As verbs, mop and mop up are synonyms defined as:

Other synonyms of mop include wipe up.

mop (noun)	mop up (noun)
cleaning implement consisting of absorbent material fastened to a handle; for cleaning floors	a concluding action

mop (verb)	mop up (verb)
make a sad face and thrust out one's lower lip	finish a task completely
to wash or wipe with or as if with a mop	defeat thoroughly
	to wash or wipe with or as if with a mop