To be, exist, become

Attested in Aelfric's Colloquy 1, Aelfric's Colloquy 2, Exeter Book Riddle 47 (wæs), Exeter Book Riddle 51 (wæs), Sellic Spell (wæs), Ætherlwold's Reforms (wæs), Ælfric's Lives of Saints - Saint Eugenia (is), Aelfric's Colloquy 3 (is), Aelfric's Colloquy 4