Definition of grey owl in US English:

grey owl

(US gray owl)

noun

  • Any of several grey-brown owls; especially the tawny owl, Strix aluco, or (in later use) (US) the eastern screech owl, Megascops (or Otus) asio.

Origin

Late 17th century; earliest use found in John Ray (1627–1705), naturalist and theologian.