Definitions for "Flathead"
Characterized by flatness of head, especially that produced by artificial means, as a certain tribe of American Indians.
A Chinook Indian. See Chinook, n., 1.
An engine with all the valves located within the block on one side of the cylinder so that the head itself is flat.
Keywords:  twin, engine, produced
The Flathead engine (V-Twin, produced from 1929 – 1972)