filter out vs filter

filter out is not a noun while filter is a noun.

Word	Noun	Adjective	Verb	Adverb
filter out	No	No	Yes	No
filter	Yes	No	Yes	No

As verbs, filter out and filter are synonyms defined as:

Other synonyms of filter out include filtrate, separate out, strain.

filter out (noun)	filter (noun)
	device that removes something from whatever passes through it
	an electrical device that alters the frequency spectrum of signals passing through it

filter out (verb)	filter (verb)
remove by passing through a filter	remove by passing through a filter
	pass through
	run or flow slowly, as in drops or in an unsteady stream