Definition of: vapor

(vā′pər) noun
1. Moisture in the air; especially, visible floating moisture, as light mist.
2. Any light, cloudy substance in the air, as smoke or fumes.
3. Any substance in the gaseous state, which, under ordinary conditions, is usually a liquid or solid.
4. A gas below its critical temperature.
5. That which is fleeting and unsubstantial.
6. A remedial agent applied by inhalation; also, a substance vaporized for use in industries.
7. Boastful swagger; vaporing.
8. plural Depression of spirits; hypochondria.
—v.t.
1. To vaporize.
—v.i.
2. To emit vapor.
3. To evaporate.
4. To make idle boasts; brag. Also Brit. va′pour. [<AF vapour, OF vapeur <L vapor steam]
—va′por·a·bil′i·ty noun
—va′por·a·ble adjective
—va′por·er noun