Hyphaeresis

a. The disappearance of ε before a vowel is often called hyphaeresis (ὑφαίρεσις omission). Thus Ionic νοσσός chick for νεοσσός, ὁρτή for ἑορτή festival; ἀδεῶς fearlessly for ἀδεέως. Here ε was sounded nearly like y and was not written.