sibilate vs speak

sibilate and speak both are verbs.

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

As verbs, speak is a hypernym of sibilate; that is, speak is a word with a broader meaning than sibilate:

Other hypernyms of sibilate include mouth, talk, utter, verbalise, verbalize.

sibilate (verb)	speak (verb)
make a sharp hissing sound, as if to show disapproval	express in speech
express or utter with a hiss	exchange thoughts; talk with
utter a sibilant	use language
pronounce with an initial sibilant	give a speech to
	make a characteristic or natural sound