Steam

To cook food, usually on a rack over simmering liquid with or without pressure.

The invisible vapor into which water is converted at the boiling point.

This is a description of a cooking method that involves using steam to cook food, as opposed to direct exposure to a flame (as in broiling) or immersion in hot liquid (as in boiling). To steam food, it can be placed in the top of a double boiler, on a rack inside a deep covered kettle with a small amount of water, or in a steamer, which is a perforated kettle set over a saucepan containing boiling water.