имя существительное [лингвистика] полугласный (звук) (w, y, но часто сюда относят плавные и назальные звуки)
noun 1. a speech sound (as [y], [w], or [r]) that has the articulation of a vowel but that is shorter in duration and is treated as a consonant in syllabication 2. a letter representing a semivowel