skim off vs skim

skim off is not a noun while skim is a noun.

Word	Noun	Adjective	Verb	Adverb
skim off	No	No	Yes	No
skim	Yes	Yes	Yes	No

As verbs, skim off and skim are synonyms defined as:

Other synonyms of skim off include cream, cream off.

skim off (noun)	skim (noun)
	reading or glancing through quickly
	a thin layer covering the surface of a liquid

skim off (adjective)	skim (adjective)
	used of milk and milk products from which the cream has been removed

skim off (verb)	skim (verb)
pick the best	read superficially
remove from the surface	move or pass swiftly and lightly over the surface of
	remove from the surface
	cause to skip over a surface
	coat (a liquid) with a layer
	travel on the surface of water
	examine hastily