sibilant vs sibilant consonant

sibilant and sibilant consonant both are nouns.

Word	Noun	Adjective	Verb	Adverb
sibilant	Yes	Yes	No	No
sibilant consonant	Yes	No	No	No

As nouns, sibilant and sibilant consonant are synonyms defined as:

sibilant and sibilant consonant: a consonant characterized by a hissing sound (like s or sh)

sibilant (noun)	sibilant consonant (noun)
a consonant characterized by a hissing sound (like s or sh)	a consonant characterized by a hissing sound (like s or sh)

sibilant (adjective)	sibilant consonant (adjective)
of speech sounds produced by forcing air through a constricted passage (as `f', `s', `z', or `th' in both `thin' and `then')