ditzy

1. (informal) Silly or scatterbrained, usually of a young woman.Examples: "The guy tossed some cash on the counter, then left with the ditzy girl and Abigail's fan."; "[…] —and she'd smile like a primly mischievous Japanese girl, or like some slyly ditzy ingenue on a talk show, all the while watching her interrogator try to fathom (though sometimes they were pretty dim and just said, “Oh”) the surprising cleverness of her answer."; "After hiring a crew of young guys and gals including loyal Jo, unlucky-in-love Frankie, strapping Bob, wisecracking Dee Dee, ditzy blonde Jonesy and titian-haired Penny, the gang drives up to the lodge."