The slow release of gas from a solid or liquid; especially the release of gases into the atmosphere of a planet(noun)
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Use "outgassing" in a sentence
"This then raised atmospheric CO2 levels, in part by outgassing from the oceans, causing the temperature to rise further."
"The outgassing is the most likely culprit, and for some reason the pinholes will persist even after a re-coat."
"If this phenomenon, called "outgassing," were to kick in, it could inundate the atmosphere with carbon dioxide, perhaps doubling or tripling the effect of the past century of human industry."