From Proto-Brythonic *kuβ̃oɨθọg. <span class="searchmatch">chefuidoc</span> almighty, powerful, great c. 1200, Latin-Old Cornish Glossary in British Library MS Cotton Vespasian A XIV...
MS Cotton Vespasian A XIV, folio 7 recto: D[eu]s om[ni]p[oten]s. Duy <span class="searchmatch">chefuidoc</span>. Almighty god. — Almighty god. Middle Cornish: dew, deu Cornish: dew Borrowed...