Etymology

From Proto-Celtic *desi, from Proto-Indo-European *dʰǵʰyes-. Cognate with Breton dec’h, Cornish de, Scottish Gaelic an-dè, and outside Celtic with Ancient Greek χθές ‎(khthés), German gestern, English yes(ter), Sanskrit ह्यस् ‎(hyas), Albanian dje.

Pronunciation

• (North Wales) IPA^(key): /ðɔɨ̯/
• (South Wales) IPA^(key): /ðɔi̯/