Etymology

From Proto-Celtic *so-, se- ‎(“this”) + *diywos ‎(“day”); compare Middle Breton hizio, Cornish hethew, and Old Irish indíu.

Pronunciation

• (standard) IPA^(key): /ˈhɛðɪu̯/
• (Powys dialect) IPA^(key): /ˈhɛðjʊ/