closing vs mop up

closing and mop up both are nouns.

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

As nouns, closing and mop up are synonyms defined as:

Other synonyms of closing include completion, culmination, windup.

closing (noun)	mop up (noun)
termination of operations	a concluding action
the act of closing something
a concluding action
approaching a particular destination; a coming closer; a narrowing of a gap
the last section of a communication

closing (adjective)	mop up (adjective)
final or ending

closing (verb)	mop up (verb)
	finish a task completely
	defeat thoroughly
	to wash or wipe with or as if with a mop