Box tortoise Meaning, Definition & Usage

  1. noun chiefly terrestrial turtle of North America; shell can be closed tightly
    box turtle.

WordNet

Definitions
  1. (Zoöl.), a land tortoise or turtle of the genera Cistudo and Emys; so named because it can withdraw entirely within its shell, which can be closed by hinged joints in the lower shell. Also, humorously, an exceedingly reticent person. Emerson.

Webster 1913