8 letters · 10 points in Scrabble
noun a consonant characterized by a hissing sound (like s or sh)
adjective of speech sounds produced by forcing air through a constricted passage (as `f', `s', `z', or `th' in both `thin' and `then')
originFrom Latin sībilāns, present active participle of sībilō (“to hiss”).
Etymology from Wiktionary, CC BY-SA 3.0