sibilate vs sibilation

sibilate is not a noun while sibilation is a noun.

Word	Noun	Adjective	Verb	Adverb
sibilate	No	No	Yes	No
sibilation	Yes	No	No	No

sibilate (noun)	sibilation (noun)
	pronunciation with a sibilant (hissing or whistling) sound
	a fricative sound (especially as an expression of disapproval)

sibilate (verb)	sibilation (verb)
make a sharp hissing sound, as if to show disapproval
express or utter with a hiss
utter a sibilant
pronounce with an initial sibilant