Greek fire

Greek fire (uncountable)

1. (historical) A highly flammable substance of unknown composition first used by the Greeks of Constantinople in the 7th century C.E. to set fire to enemy ships, buildings etc.
   • 1819, Sir Walter Scott, Ivanhoe:

     “There is yet spirit in him,” said Malvoisin apart to Mont–Fitchet, “were it well directed — but, like the Greek fire, it burns whatever approaches it.”

• Grecian fire