A dim-witted, useless, or unintelligent person. I can't believe I got paired with such an airhead for this assignment. He's not going to get any work done at all!
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
n. a stupid person. (Someone with air where there should be brains.) Some airbrain put mustard in the ketchup dispenser. Bart seems like such an airhead, but he’s all heart.
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.