gas mark
Noun
Meaning
gas mark (plural gas marks)
(chiefly Britain) Any of the measurements on a scale of temperatures in domestic gas cookers.
Synonym: (archaic) Regulo mark
Roast potatoes need 25 minutes at gas mark 7.
Examples
Bake for one-and-a-half hours, in a moderate oven (Gas Mark 4/180°C/350°F).