nonsyllabic

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 a syllable (as the second vowel in a falling diphthong); "the nonsyllabic `n'' in `botany'' when it is pronounced `botny''"; "the nonsyllabic `i'' in `oi''"

(of speech sounds) not forming or capable of forming the nucleus of a syllable; "initial ''l'' in ''little'' is nonsyllabic"