1. (adj)sibilant, sibilant consonant a consonant characterized by a hissing sound (like s or sh) Synonyms: sibilant consonant, sibilant Antonyms: hard
2. (adj)fricative, continuant, sibilant, spirant, strident of speech sounds produced by forcing air through a constricted passage (as `f', `s', `z', or `th' in both `thin' and `then') Synonyms: raucous, shrill, sibilant, fricative, clamorous, clamant, blatant, vociferous, continuant, strident, spirant Antonyms: hard