Outgas

Part of speech: verb

Definitions

1. To emit gaseous substances from a solid or liquid state as a result of heat or chemical reactions
2. To discharge volatile compounds from materials when subjected to heat or during chemical transformation
3. To discharge gas that was previously dissolved, trapped, or absorbed within a solid or liquid material

Etymology: "Outgas" is a plain compound: the prefix "out-" joined to "gas." The "out-" traces back through Old English "ūt" and Proto-Germanic "ūt" to a much older root, and it carried the sense of motion or release from within long before it was attached to chemistry. The "gas" half is a more unusual story. It was coined by the Flemish chemist Jan Baptist van Helmont in the 1600s, who took the Greek "khaos," meaning an empty space or the primordial void, and reshaped it into a new word for the vapours he was studying. Some of the Greek connection runs through the Dutch "gas" as well, since English borrowed the term from Dutch. Put together, "outgas" describes a substance quietly escaping from a solid or liquid where it had been held. The verb is used especially in materials science and space engineering, where a sealed component releases gas it has absorbed over time.

Synonyms: vent, release, evacuate, exhale, exude