tryma

/ˈtraɪmə/
noun
  1. A type of fruit, such as a walnut or hickory nut, that has a hard shell surrounded by a fleshy outer layer that splits open when ripe.
    • The walnut is a classic example of a tryma, with its green husk and hard inner shell.
    • When the tryma ripens, the outer layer cracks open to reveal the nut inside.
    • Botanists classify the hickory nut as a tryma because of its splitting husk.