Added 9 October 2026 isaiah noun Categories: PeopleLanguageUncommon Words noun ! Definition from WordNet 3.1, Princeton University. More about isaiah at Wordnik → Where our words come from → (Old Testament) the first of the major Hebrew prophets (8th century BC). An Old Testament book consisting of Isaiah's prophecies. Related Words: isaacissacdeuteroisakprophesiesxlprophetvisionaryoracledivinersoothsayerseer Back to today's word