Definitions for "Vowels"
The letters, a, e, i, o and u. (and sometimes y) All the others are consonants.
a, e, i, o, u and sometimes y and w; made without any air obstruction
The letters a, e, i, o, and u and sometimes y. Some vowels are long (e.g., ate, ice), some are short (e.g., am, us).