11 letters · 18 points in Scrabble
adjective not forming a syllable or the nucleus of a syllable; consisting of a consonant sound accompanied in the same syllable by a vowel sound or consisting of a vowel sound dominated by other vowel sounds in
adjective (of speech sounds) not forming or capable of forming the nucleus of a syllable
originFrom non- + syllabic.
Etymology from Wiktionary, CC BY-SA 3.0