polish up vs polish

polish up is not a noun while polish is a noun.

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

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

polish up and polish: bring to a highly developed, finished, or refined state

Other synonyms of polish up include brush up, round, round off.

polish up (noun)	polish (noun)
	the property of being smooth and shiny
	a highly developed state of perfection; having a flawless or impeccable quality
	a preparation used in polishing

polish up (verb)	polish (verb)
bring to a highly developed, finished, or refined state	bring to a highly developed, finished, or refined state
	improve or perfect by pruning or polishing
	make (a surface) shine