Freeze-dry definition

To preserve (food, for example) by rapid freezing and drying in a high vacuum.

To subject (food, vaccines, etc.) to quick-freezing followed by drying under high vacuum at a low temperature: a freeze-dried product, as food, will keep for long periods at room temperature.

To preserve a substance, such as food, by freezing it rapidly and placing it in a vacuum chamber, where the water frozen in the substance evaporates through sublimation.