tortoiseshell

As a noun, this term refers to the physical material harvested from turtles. Because it is treated as a mass noun representing a substance or material, it is typically used in the singular form without a plural. It carries a connotation of luxury and antiquity, though in modern contexts, it often implies a synthetic imitation due to conservation laws.

As an adjective, the word describes a specific color pattern. In the context of animals, particularly cats, it refers to a distinct genetic coat pattern of orange, black, and cream. This usage is purely descriptive and does not imply the animal is related to a tortoise.