n. 1. One who, or that which, races, or contends in a race; esp., a race horse. [ 1913 Webster ]
And bade the nimblest racer seize the prize. Pope. [ 1913 Webster ]
2. (Zool.) The common American black snake. [ 1913 Webster ]
3. (Mil.) One of the circular iron or steel rails on which the chassis of a heavy gun is turned. [ 1913 Webster ]