1. A state of depression
   "he had a bad case of the vapours";
   - blues, blue devils [archaic], megrims, vapors [US]

1. A visible suspension in the air of particles of some substance
   "The vapour from the chemical reaction filled the laboratory";
   - vapor [US]
    
2. The process of becoming a vapour
   "The rapid vapour of the liquid nitrogen created a fog-like effect";
   - vaporization, vaporisation [Brit], vapor [US], evaporation

1. [Brit, Cdn] Speak (about unimportant matters) rapidly and incessantly
   "The old man vapoured on about the weather";
   - chatter, piffle [informal], palaver [informal], prate, tittle-tattle, twaddle [informal], clack [informal], maunder, prattle, blab [informal], gibber, tattle, blabber [informal], gabble, vapor [US], rabbit [Brit, informal], jibber-jabber, witter [Brit, informal], twattle [UK, dialect], yatter [Brit, informal], yabber [informal]
    
2. [N. Amer] Become or emit vapour
   "The liquid began to vapour as it heated up";
   - vapor [US]

Type of: depression, mouth, phase change, phase transition, physical change, speak, state change, suspension, talk, utter, verbalise [Brit], verbalize

Encyclopedia: Vapours