Green’s Dictionary of Slang

airhead adj.

also airheaded
[airhead n. (1)]

(US) stupid.

[US](con. 1970) J.M. Del Vecchio 13th Valley (1983) 200: You fuckin airhead assholes give me a case of the ass.
[US]G.V. Higgins Patriot Game (1985) 156: And there you sit, chewing the Irish bubblegum with a couple of airheaded, tittering matrons.
[US]A. Maupin Further Tales of the City (1984) 119: That airhead debutante.
[Aus]Bug (Aus.) 1 Oct. [Internet] She had this private school accent, and was tarted up like an airhead game show hostess.
[US]C. Hiaasen Skinny Dip 265: And me, the classic airhead blonde, I believed him.