late 14c., in alchemy, "process of purifying by heating into a vapor," from Medieval Latin sublimationem (nominative sublimatio) "refinement," literally "a lifting up, deliverance," from Latin sublimare "to raise, elevate," from sublimis "lofty" (see sublime). Psychological sense is first recorded 1910, probably influenced by subliminal.
The process of changing from a solid to a gas without passing through an intermediate liquid phase. Carbon dioxide, at a pressure of one atmosphere, sublimates at about -78 degrees Celsius. Ice and snow on the Earth's surface also sublimate at temperatures below the freezing point of water. Compare deposition.
In Freudian psychology, a defense mechanism by which the individual satisfies a socially prohibited instinctive drive (usually sexual or aggressive) through the substitution of socially acceptable behavior. For example, someone with strong sexual drives who paints nude portraits may be engaging in sublimation.