definition of
sibilant

[1] #1 sibilant n. [sibilant consonant] a consonant characterized by a hissing sound (like s or sh). wn

[2] #2 sibilant s. [fricative, continuant, spirant, strident] of speech sounds produced by forcing air through a constricted passage (as 'f', 's', 'z', or 'th' in both 'thin' and 'then'). wn