tor·toise·shell also tor·toise shell 
(tôrtĭs-shĕl′)
(tôrtĭs-shĕl′)n.
1.
a. The mottled, horny, translucent, brownish covering of the carapace of certain tortoises or turtles, especially the hawksbill, formerly widely used to make combs, jewelry, and other articles.
b. A synthetic imitation of natural tortoiseshell.
2. See hawksbill.
3. A domestic cat having a coat with irregular patches of different colors, usually black and reddish-orange.
4. Any of several butterflies, chiefly of the genus Nymphalis, having wings with orange, black, and brown markings.
tortoise-shell′ adj.