sibilation vs sibilate

sibilation is a noun but sibilate is not a noun.

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

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

sibilation (verb)	sibilate (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