Any fish in the Platycephalidae family.
(plural only "flatheads") A type of screw or bolt designed to fit in a countersink so that it sits flush with a surface.
(plural only "flatheads") A type of engine that has the valves placed in the engine block beside the piston, instead of in the cylinder head, as in an overhead valve engine.
A large freshwater catfish native to North America, Pylodictis olivaris.