an amount of a liquid or substance that fills a spoon/cup but does not go above the edges, used as a measure in cooking

Add two level spoonfuls of cocoa powder to the mixture.

Put a level tablespoonful of butter into the pan.

Use one level teaspoonful of salt for every pint of water.

You will need two level cupfuls of flour.

Stir in one level cupful of brown sugar.

See also: level adjective (FLAT)