Learn English idioms with meanings and examples

🌎Region: International 📊Difficulty Level:intermediate

full of hot air

Not sincere or serious; talking confidently but with little truth, value, or substance.

From the idea of something inflated with air—big in size but empty in substance. Popularized by images like balloons/blimps and the notion of “hot air” as empty talk.

A critical, informal way to say someone’s talk is empty or exaggerated. Often used about promises, boasts, pitches, or grand claims.

  • He talks confidently about the project, but he’s full of hot air and never delivers.
  • Don’t let that influencer convince you—most of what he says is full of hot air.
  • Her speech sounded inspiring at first, yet it turned out to be full of hot air.
  • The salesman promised huge savings, but my dad said he was full of hot air.
  • I used to think he had a plan, until I realized he was full of hot air.

Common patterns: “be full of hot air” and “(someone’s) talk/claims are full of hot air.” “Hot air” is usually uncountable here; rarely used in other tenses except with “be.”

  • all talk (and no action)
  • blowhard
  • empty rhetoric
  • big talk
  • talking through one’s hat
  • sincere
  • genuine
  • substantive
  • credible