Definition of Petermas in English:

Petermas

Pronunciation /ˈpiːtəmas/

noun

rare
  • Originally: the feast of St Peter ad Vincula (1 August); = "Lammas". Later also: the feast of St Peter and St Paul (29 June); = Petertide .

Origin

Middle English. From Peter + mass, after earlier genitive construction (Saint) Peter's Mass.