D defs.my
Entry 2 senses Webster, 1913

Costard

/(k?s"t?rd)/ · Cos·tard · IPA /ˈkɒs.tə(ɹ)d/
01 n. An apple, large and round like the head.
  1. 1.
    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.” — Muffett.
  2. 2.
    The head; -- used contemptuously.
    “Try whether your costard or my bat be the harder.” Shak.