into thin air

Idioms and Phrases

Also, into the blue . Completely disappeared, as in The report was here on my desk and now it's gone, vanished into thin air , or I don't know where they've gone—into the blue, for all I know . Both of these hyperbolic expressions, often preceded by vanish as in the first example, use the rarefied atmosphere far above the earth as a metaphor for an unknown location. Shakespeare wrote of ghosts that “melted . . . into thin air” ( The Tempest , 4:1). An antonym for both is out of thin air , meaning “from an unknown place or source.” For example, She made up this excuse out of thin air , or The car appeared out of thin air . However, out of the blue is not precisely an antonym (see under out of a clear blue sky ).