sibilant has definitions from the fields of linguistics,phonetics
1
[ adjective ] of speech sounds produced by forcing air through a constricted passage (as `f', `s', `z', or `th' in both `thin' and `then')

Synonyms

spirant fricative

Related terms

soft

2
[ noun ] (linguistics,phonetics) a consonant characterized by a hissing sound (like s or sh)
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