Cos"tard (k?s"t?rd), n. [Prob. fr. OF. coste rib, side, F. cote, and meaning orig., a ribbed apple, from the ribs or angles on its sides. See Coast.]
An apple, large and round like the head.
Some [apples] consist more of air than water . . . ; others more of water than wind, as your costards and pomewaters.
The head; -- used contemptuously.
Try whether your costard or my bat be the harder.
© Webster 1913.