headshaking vs headshake

headshaking and headshake both are nouns.

Word	Noun	Adjective	Verb	Adverb
headshaking	Yes	No	No	No
headshake	Yes	No	No	No

As nouns, headshaking and headshake are synonyms defined as:

headshaking and headshake: the act of turning your head left and right to signify denial or disbelief or bemusement

headshaking (noun)	headshake (noun)
the act of turning your head left and right to signify denial or disbelief or bemusement	the act of turning your head left and right to signify denial or disbelief or bemusement