comb vs comb out

comb is a noun but comb out is not a noun.

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

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

Other synonyms of comb include disentangle.

comb (noun)	comb out (noun)
the act of drawing a comb through hair
ciliated comb-like swimming plate of a ctenophore
the fleshy red crest on the head of the domestic fowl and other gallinaceous birds
a flat device with narrow pointed teeth on one edge; disentangles or arranges hair
any of several tools for straightening fibers

comb (verb)	comb out (verb)
smoothen and neaten with or as with a comb	smoothen and neaten with or as with a comb
search thoroughly	remove unwanted elements
straighten with a comb