Real Dictionary

tooth
Your teeth are the hard white objects in your mouth, which you use for biting and chewing.

tooth in American English
any of a set of hard, bonelike structures set in the jaws of most vertebrates and used for biting, tearing, and chewing: a tooth consists typically of a sensitive, vascular pulp surrounded by dentin and coated on the crown with enamel and on the root with
noun: one of the hard bodies or processes usually attached in a row to each jaw, serving for the prehension and mastication of food, as weapons of attack or defense, etc., and in mammals typically composed chiefly of dentin surrounding a sensitive pulp and cove

tooth in British English
noun: any of various bonelike structures set in the jaws of most vertebrates and modified, according to the species, for biting, tearing, or chewing

tooth in Mechanical Engineering
noun: The teeth on a gear, sprocket, or rack are the parts that stick out from it and mate with teeth on another part to transmit motion.