tooth / toō[unvoicedth]/ • n. (pl. teeth / tē[unvoicedth]/ ) 1. each of a set of hard, bony enamel-coated structures in the jaws of most vertebrates, used for biting and chewing. ∎  a similar hard, pointed structure in invertebrate animals, typically functioning in the mechanical breakdown of food. ∎  an appetite or liking for a particular thing. ∎  roughness given to a surface to allow color or glue to adhere. ∎  (teeth) fig. genuine force or effectiveness of a body or in a law or agreement: the Charter would be fine if it had teeth and could be enforced. 2. a projecting part on a tool or other instrument, esp. one of a series that function or engage together, such as a cog on a gearwheel or a point on a saw or comb. ∎  a projecting part on an animal or plant, esp. one of a jagged or dentate row on the margin of a leaf or shell. PHRASES: armed to the teeth formidably armed. fight tooth and nail fight fiercely. get (or sink) one's teeth into work energetically and productively on (a task): the course gives students something to get their teeth into. in the teeth of directly against (the wind). ∎  in spite of or contrary to (opposition or difficulty): we defended it in the teeth of persecution. set someone's teeth on edgesee edge.DERIVATIVES: toothed adj. tooth·like / -ˌlīk/ adj.

tooth Any of the hard structures in vertebrates that are used principally for biting and chewing food but also for attack, grooming, and other functions. In fish and amphibians the teeth occur all over the palate, but in higher vertebrates they are concentrated on the jaws. They evolved in cartilaginous fish as modified placoid scales, and this is reflected in their structure: a body of bony dentine with a central pulp cavity and an outer covering of enamel on the exposed surface (crown). The portion of the tooth embedded in the jawbone is the root (see illustration).

In mammals there are four different types of teeth, specialized for different functions (see canine tooth; incisor; molar; premolar). Their number varies with the species (see dental formula). See also deciduous teeth; permanent teeth.

tooth (tooth) n. (pl. teeth) one of the hard structures in the mouth used for cutting and chewing food. Each tooth is embedded in a socket in the jawbone, to which it is attached by the periodontal membrane. The exposed part of the tooth (crown) is covered with enamel and the part within the bone (root) is coated with cementum; the bulk of the tooth consists of dentine enclosing the pulp. There are four different types of teeth (see canine, incisor, premolar, molar). See illustration overleaf. See also dentition.

tooth. Late-Romanesque and First Pointed Gothic ornament consisting of a series of projecting hollow pierced pyramids, also known as dog-tooth, or tooth ornament, sometimes with the points and bases of the pyramidal form transformed into stylized flowers.

tooth fight tooth and nail fight very fiercely; recorded from the mid 16th century, originally in the form ‘with tooth and nail’, that is, by biting and scratching.

See also an eye for an eye and a tooth for a tooth, Nature red in tooth and claw at nature, the tongue always returns to a sore tooth.