sibilant
1. sib.i.lant \'sib-*-l*nt\ aj [L sibilant-, sibilans, prp. of sibilare to hiss, whistle, of] imit. origin : having, containing, or producing the sound of or a sound resembling tha t of the s or the sh in sash {a ~ affricate} {a ~ snake} - sib.i.lant.ly av 2. sibilant n : a sibilant speech sound (as English /s/, /z -, /sh/, /zh/, /ch(=tsh)/, or /j(=dzh)/)