comb vs combing

comb and combing both are nouns.

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

As nouns, comb and combing are synonyms defined as:

comb (noun)	combing (noun)
the act of drawing a comb through hair	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)	combing (verb)
smoothen and neaten with or as with a comb
search thoroughly
straighten with a comb