a flat screw head.
noun 1. a yellow and brown catfish, Pylodictus olivaris, common in the central U.S., having a flattened head and a projecting lower jaw.
adjective Stupid: The speaker was a flatheaded idiot (1880+)
[flat-hed-id] /ˈflætˌhɛd ɪd/ noun 1. (def 1).
noun 1. the larva of a metallic wood-boring beetle, having an expanded and flattened anterior end.