Semivowel

In phonetics and phonology, a semivowel, glide or semiconsonant is a sound that is phonetically similar to a vowel sound but functions as the syllable boundary, rather than as the nucleus of a syllable.[1] Examples of semivowels in English are the consonants y and w in yes and west, respectively. Written /j w/ in IPA, y and w are near to the vowels ee and oo in seen and moon, written / / in IPA. The term glide may alternatively refer to any type of transitional sound, not necessarily a semivowel.[2]