tortoiseshell, n. & adj.
1 the yellowish-brown mottled or clouded outer shell of some turtles, used for decorative hair-combs, jewellery, etc.
2 a = tortoiseshell cat. b = tortoiseshell butterfly.
--adj. having the colouring or appearance of tortoiseshell.
tortoiseshell butterfly any of various butterflies, esp. of the genus Aglais or Nymphalis, with wings mottled like tortoiseshell. tortoiseshell cat a domestic cat with markings resembling tortoiseshell.