1. steam pressure
Wikipedia definition
2. Vapor pressureVapor pressure or equilibrium vapor pressure is the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases (solid or liquid) at a given temperature in a closed system. The equilibrium vapor pressure is an indication of a liquid's evaporation rate. It relates to the tendency of particles to escape from the liquid (or a solid). A substance with a high vapor pressure at normal temperatures is often referred to as volatile.
Read “Vapor pressure” on English Wikipedia
Read “蒸気圧” on Japanese Wikipedia
Read “Vapor pressure” on DBpedia


to talk about this word.