adjective

stupid; very foolish.

a brainless bimbo

stupid,foolish,witless,unintelligent,ignorant,mindless,idiotic,imbecilic,imbecile,half-witted,simple-minded,silly,empty-headed,half-baked,dumb,brain-dead,moronic,cretinous,thick,thickheaded,dopey,dozy,birdbrained,pea-brained,pinheaded,dippy,lamebrained,dunderheaded,wooden-headed,divvy,as thick as two short planks,glaikit,dumb-ass,chowderheaded,dof,dotish