A clever way to call someone an airhead (playing off the traditional meaning of pneumatic, which is, "pertaining to or filled with air.") Usually used in reference to women who are bubbly and nice, but dumb as a box of rocks.
Girl 1: That girl is such an idiot--she probably can't remember how to spell her own name.
Girl 2: Be nice, she's just a little....pneumatic.
Girl 2: Be nice, she's just a little....pneumatic.
by itcomesandgoes May 11, 2010