1. [informal] Insincere or vague talk with empty promises etc. that is supposed to impress
   "mere hot air";
   - empty words, empty talk, rhetoric, bluster
    
2. Air that has been heated and tends to rise
   "The hot air balloon lifted off as it was filled with heated air"

Type of: air, bunk [informal], hokum [informal], meaninglessness, nonsense, nonsensicality

Encyclopedia: Hot air