tooth

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. One of a set of hard, bonelike structures rooted in sockets in the jaws of vertebrates, typically composed of a core of soft pulp surrounded by a layer of hard dentin that is coated with cementum or enamel at the crown and used for biting or chewing food or as a means of attack or defense.
2. n. A similar structure in invertebrates, such as one of the pointed denticles or ridges on the exoskeleton of an arthropod or the shell of a mollusk.
3. n. A projecting part resembling a tooth in shape or function, as on a comb, gear, or saw.
4. n. A small, notched projection along a margin, especially of a leaf. Also called dent².
5. n. A rough surface, as of paper or metal.
6. n. Something that injures or destroys with force. Often used in the plural: the teeth of the blizzard.
7. n. Effective means of enforcement; muscle: "This . . . puts real teeth into something where there has been only lip service” ( Ellen Convisser).
8. n. Taste or appetite: She always had a sweet tooth.
9. v. To furnish (a tool, for example) with teeth.
10. v. To make a jagged edge on.
11. v. To become interlocked; mesh.
12. idiom. get Slang To be actively involved in; get a firm grasp of.
13. idiom. show To express a readiness to fight; threaten defiantly.
14. idiom. to the teeth Lacking nothing; completely: armed to the teeth; dressed to the teeth.

Century Dictionary and Cyclopedia

1. n. The topography of the tooth, as now described, is shown in the cuts.
2. n. A roughened surface, as of a paper prepared for pastels.
3. n. In masonry, one of the several projecting ends of stones or bricks already built into a wall and left at an unfinished end of it to facilitate the fitting of another piece of wall to the first one.
4. n. A hard (horny, dentinal, osseous, chitinous, calcareous, or silicious) body or substance, in the mouth, pharynx, gullet, or stomach of an animal, serving primarily for the apprehension, mastication, or trituration of food, and secondarily as a weapon of attack or defense, and for a variety of other purposes, as digging in the ground, climbing, articulation of vocal sounds, etc. In man and mammals generally teeth are confined to the mucous membrane of the premaxillary, supramaxillary, and inframaxillary bones, and true teeth are present throughout the class, with a few exceptions. (See Edentata, Monotremata.) True teeth existed in Cretaceous birds, as the Archæopteryx, Hesperornis, and Ichthyornis; no recent birds have teeth. (See cut under Ichthyornis.) In reptiles, batrachians, and fishes teeth are the rule; in these classes they may be not only on the maxillary bones of either or both jaws, but also on the palate-bones, pharyngeal bones, vomer, etc. Chelonians are devoid of teeth, their horny beaks answering for biting, as is also the case with birds. True teeth are usually attached to the bones of the jaws by being socketed in pits or grooves called alveoli, this mode of articulation being termed gomphosis. In reptiles, etc., the attachment to bone may be more intimate, and may occur in several ways, whence the terms acrodont, holcodont, pleurodont, thecodont, etc. True teeth in vertebrates are enderonic structures which develop from odontoblasts, and consist chiefly of a substance called dentin, to which may be added cement and enamel; which hard structures, as a rule, are disposed about a pulp-cavity, filled with soft tooth-pulp, or the nutrient and nervous structures of the tooth. This cavity may close up or remain wide open; in the latter case, teeth grow perennially or for an indefinite period. (See Glires, Rodentia.) Dentin resembles bone in most respects, and differs especially in the fineness and parallelism of the tubules which radiate from the central cavity. Ivory is a variety of dentin. The hard tissues of teeth are sometimes intricately folded (see labyrinthodont, with cut); but individual teeth are seldom compounded (see, however, Orycteropodidæ). Teeth of monotremes, when present, are horny and not dentinal. There may be one or several rows of maxillary teeth, which successively come into position, as the molars of the elephant, or are simultaneously in position. as is the rule. In all mammals true teeth are confined to a single row, upon the bones above mentioned; and in none are there more than two sets of teeth. Mammals with only one set of teeth are termed monophyodont; those with two sets, diphyodont. In diphyodont mammals the first or temporary set of teeth are termed milk-teeth; these are sometimes shed in the womb; the second set are the permanent teeth. According to their special shapes, or their special seats, teeth of diphyodonts are divided into three sets—incisors, canines, and molars. An incisor of the upper jaw is any tooth situated upon the premaxillary bone; an incisor of the under jaw is any tooth of the mandible which opposes a superior incisor. An upper canine is the single first or most anterior tooth of the supramaxillary bone; an under canine is the tooth which opposes this one, and on closure of the mouth passes in front of it. A molar tooth is one of the back teeth, or grinders. Molars are divided into false molars, premolars, or bicuspids, and true molars; the premolars being those which are preceded by milk-molars, the molars proper being those which have no predecessors. Thus, the permanent dentition of a diphyodont mammal differs from the milk-dentition by the addition of true molars. This classification of the teeth enables us to construct convenient dental formulæ. (See dental formula, under dental,) The incisors are generally simple, single-rooted, nipping or cutting teeth, whence the name (but see soricident, with cut). The canine is likewise a simple tooth. but one which in the Carnivora, as a dog or cat, is lengthened and even saber-like (the name is taken from its condition in the dog, and retained whether this tooth be actually caniniform or not). The molar, grinding, or crushing teeth usually have more than one root or fang, and more than one cusp or prominence upon the crown; they are hence called bicuspid, tricuspid, multicuspid, etc., as the premolars (bicuspids) and molars (multicuspids) of man; their crowns are variously tuberculous, giving rise to special descriptive terms, as bunodont, symborodont, bathmodont, selenodont, mastodont, etc., and also bi-, tri-, quadri-, quinque-tuberculate, etc. One molar or premolar above and below, in carnivorous quadrupeds, is specially modified with a sharp crest which cuts against its fellow of the other jaw like a scissor-blade; such a tooth is termed sectorial or carnassial. A tooth (incisor or canine) which projects from the mouth is termed a tusk or tush, as in the elephant, walrus, narwhal, wild boar and others of the pig family, and the fossil saber-toothed cats (Machærodontinæ), (See cuts under Monodon, saber-toothed, and tusk.) A tooth may be peculiarly folded upon itself to serve as a channel for the conveyance of a poisonous fluid, as in the rattlesnake: such a tooth is termed a fang. (See poison-fang, and cut under (rotalus.)A tooth is commonly divided into a crown, a neck or cingulum, embraced by the gum, and a fang or root—the latter, which may be multiple, being socketed in the alveolar process of the jaw. Any animal's set of teeth, or the character of that set, constitutes its dentition. Decay of the teeth is caries, and a decaying tooth is said to be carious. The scientific study and description of teeth is odontology or odontography. In pursuing this subject, see the various words above italicized, and many of the cuts cited under skull, as well as those under Desmodontes, maxillary, palate, Pythonidæ, scalpriform, and supramaxillary.
5. n. In Invertebrata, one of various hard bodies, presenting great variety of position and structure, which may occur in the alimentary canal from the month to the stomach. Such teeth are always ecderonic, cuticular, or epithelial structures, as the numerous teeth upon the lingual ribbon of gastropods, as the snail. These are true teeth, of chitinous structure, very numerous, and very regularly arranged in cross-rows each of which usually consists of differently shaped teeth distinguished by name (as median, admedian, uncinal, etc.), and the whole character of which is important in classification. (See odontophore, cuts under radula and ribbon, and various classificatory terms cited under radula.) Various hard tooth-like or jaw-like projections receive the name of teeth, as certain chitinous protuberances, called cardiac or gastric teeth, in the stomach of the lobster, crab, etc.
6. n. In zoology, a projection resembling or likened to a tooth. Specifically— A horny process of the cutting edge of the beak of many birds, as the falcon and shrike. See cut under dentirostral.
7. n. In botany, any small pointed marginal lobe, especially of a leaf: in mosses applied to the delicate fringe of processes about the mouth of the capsule, collectively known as the peristome. See peristome, Musci, and cuts under cilium and Dicranum.
8. n. Any projection corresponding to or resembling the tooth of an animal in shape, position, or office; a small, narrow, projecting piece, usually one of a set. One of the projections of a comb, a saw, a file, a harrow, or a rake.
9. n. One of the tines or prongs of a fork.
10. n. One of the sharp wires of a carding-instrument.
11. n. One of a series of projections on the edge of a wheel which catch on corresponding parts of a wheel or other body; a cog. See cut under pinion.
12. n. plural In a rose-cut diamond, the lower zone of facets. They form a truncated cone-shaped base for the crown.
13. n. In veneering, the roughness made by the toothing-plane on the surfaces to be glued together to afford a good hold for the glue.
14. n. Figuratively, a fang; the sharp or distressing part of anything.
15. n. Palate; relish; taste, literally or figuratively. Compare a sweet tooth, below.
16. n. Keep; maintenance.
17. n. To one's face; openly.
18. n. Straight against: noting direction: as, to walk in the teeth of the wind.
19. n. In the face or presence of; before.
20. n. The processes or serration of the mandibles of any insect, as a stag-beetle.
21. To bite; taste.
22. To furnish with teeth: as, to tooth a rake.
23. To indent; cut into teeth; jag.
24. To lock one in another.
25. To teethe.
26. To interlock, as cog-wheels.

Wiktionary

1. n. A hard, calcareous structure present in the mouth of many vertebrate animals, generally used for eating.
2. n. A sharp projection on the blade of a saw or similar implement.
3. n. A projection on the edge of a gear that meshes with similar projections on adjacent gears, or on the circumference of a cog that engages with a chain.
4. n. botany A pointed projection from the margin of a leaf.
5. v. To provide or furnish with teeth.
6. v. To indent; to jag.
7. v. To lock into each other, like gear wheels.

GNU Webster's 1913

1. n. (Anat.) One of the hard, bony appendages which are borne on the jaws, or on other bones in the walls of the mouth or pharynx of most vertebrates, and which usually aid in the prehension and mastication of food.
2. n. Fig.: Taste; palate.
3. n. Any projection corresponding to the tooth of an animal, in shape, position, or office.
4. n. A projecting member resembling a tenon, but fitting into a mortise that is only sunk, not pierced through.
5. n. One of several steps, or offsets, in a tusk. See Tusk.
6. n. (Nat. Hist.), (Bot.) An angular or prominence on any edge one of the appendages at the mouth of the capsule of a moss. See Peristome.
7. n. (Zoöl.) Any hard calcareous or chitinous organ found in the mouth of various invertebrates and used in feeding or procuring food.
8. v. To furnish with teeth.
9. v. To indent; to jag.
10. v. To lock into each other. See Tooth, n., 4.

WordNet 3.0

1. n. one of a number of uniform projections on a gear
2. n. hard bonelike structures in the jaws of vertebrates; used for biting and chewing or for attack and defense
3. n. something resembling the tooth of an animal
4. n. toothlike structure in invertebrates found in the mouth or alimentary canal or on a shell
5. n. a means of enforcement