What is "tooth"

Tooth \Tooth\ (t[=oo]th), n.; pl. Teeth (t[=e]th). [OE. toth,tooth, AS. t[=o][eth]; akin to OFries. t[=o]th, OS. & D. tand, OHG. zang, zan, G. zahn, Icel. t["o]nn, Sw. & Dan. tand, Goth. tumpus, Lith. dantis, W. dant, L. dens, dentis, Gr. 'odoy`s, 'odo`ntos, Skr. danta; probably originally the p. pr. of the verb to eat. [root]239. Cf. Eat, Dandelion, Dent the tooth of a wheel, Dental, Dentist, Indent, Tine of a fork, Tusk. ]

1. (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.

   Note: The hard parts of teeth are principally made up of dentine, or ivory, and a very hard substance called enamel. These are variously combined in different animals. Each tooth consist of three parts, a crown, or body, projecting above the gum, one or more fangs imbedded in the jaw, and the neck, or intermediate part. In some animals one or more of the teeth are modified into tusks which project from the mouth, as in both sexes of the elephant and of the walrus, and in the male narwhal. In adult man there are thirty-two teeth, composed largely of dentine, but the crowns are covered with enamel, and the fangs with a layer of bone called cementum. Of the eight teeth on each half of each jaw, the two in front are incisors, then come one canine, cuspid, or dog tooth, two bicuspids, or false molars, and three molars, or grinding teeth. The milk, or temporary, teeth are only twenty in number, there being two incisors, one canine, and two molars on each half of each jaw. The last molars, or wisdom teeth, usually appear long after the others, and occasionally do not appear above the jaw at all.

   How sharper than a serpent's tooth it is To have a thankless child!
   --Shak.

2. Fig.: Taste; palate.

   These are not dishes for thy dainty tooth.
   --Dryden.

3. Any projection corresponding to the tooth of an animal, in shape, position, or office; as, the teeth, or cogs, of a cogwheel; a tooth, prong, or tine, of a fork; a tooth, or the teeth, of a rake, a saw, a file, a card.

4. 1. A projecting member resembling a tenon, but fitting into a mortise that is only sunk, not pierced through.

   2. One of several steps, or offsets, in a tusk. See Tusk.

5. (Nat. Hist.) An angular or prominence on any edge; as, a tooth on the scale of a fish, or on a leaf of a plant; specifically (Bot.), one of the appendages at the mouth of the capsule of a moss. See Peristome.

6. (Zo["o]l.) Any hard calcareous or chitinous organ found in the mouth of various invertebrates and used in feeding or procuring food; as, the teeth of a mollusk or a starfish. In spite of the teeth, in defiance of opposition; in opposition to every effort. In the teeth, directly; in direct opposition; in front. ``Nor strive with all the tempest in my teeth.'' --Pope. To cast in the teeth, to report reproachfully; to taunt or insult one with. Tooth and nail, as if by biting and scratching; with one's utmost power; by all possible means. --L'Estrange. ``I shall fight tooth and nail for international copyright.'' --Charles Reade. Tooth coralline (Zo["o]l.), any sertularian hydroid. Tooth edge, the sensation excited in the teeth by grating sounds, and by the touch of certain substances, as keen acids. Tooth key, an instrument used to extract teeth by a motion resembling that of turning a key. Tooth net, a large fishing net anchored. [Scot.] --Jamieson. Tooth ornament. (Arch.) Same as Dogtooth, n., 2. Tooth powder, a powder for cleaning the teeth; a dentifrice. Tooth rash. (Med.) See Red-gum,

   1. To show the teeth, to threaten. ``When the Law shows her teeth, but dares not bite.''
      --Young.

      To the teeth, in open opposition; directly to one's face. ``That I shall live, and tell him to his teeth .''
      --Shak.

Tooth \Tooth\, v. t. [imp. & p. p. Toothed; p. pr. & vb. n. Toothing.]

1. To furnish with teeth.

   The twin cards toothed with glittering wire.
   --Wordsworth.

2. To indent; to jag; as, to tooth a saw.

3. To lock into each other. See Tooth, n.,

4. 
   --Moxon.

Old English toð (plural teð), from Proto-Germanic *tan-thuz (cognates: Old Saxon, Danish, Swedish, Dutch tand, Old Norse tönn, Old Frisian toth, Old High German zand, German Zahn, Gothic tunþus), from PIE *dent- "tooth" (cognates: Sanskrit danta, Greek odontos, Latin dens, Lithuanian dantis, Old Irish det, Welsh dent). Plural form teeth is an instance of i-mutation.\n

\nApplication to tooth-like parts of other objects (saws, combs, etc.) first recorded 1520s. Tooth and nail as weapons is from 1530s. The tooth-fairy is attested from 1964.

n. 1 A hard, calcareous structure present in the mouth of many vertebrate animals, generally used for eating. 2 A sharp projection on the blade of a saw or similar implement. 3 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 (context botany English) A pointed projection from the margin of a leaf. 5 (context animation English) The rough surface of some kinds of cel or other films that allow better adhesion of artwork. 6 (context figurative English) taste; palate vb. 1 To provide or furnish with teeth. 2 To indent; to jag. 3 To lock into each other, like gear wheels.

1. n. hard bonelike structures in the jaws of vertebrates; used for biting and chewing or for attack and defense

2. something resembling the tooth of an animal

3. toothlike structure in invertebrates found in the mouth or alimentary canal or on a shell

4. a means of enforcement; "the treaty had no teeth in it"

5. one of a number of uniform projections on a gear

6. [also: teeth (pl)]

A tooth (plural teeth) is a small, calcified, whitish structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores, also use teeth for hunting or for defensive purposes. The roots of teeth are covered by gums. Teeth are not made of bone, but rather of multiple tissues of varying density and hardness. The cellular tissues that ultimately become teeth originate from the embryonic germ layer, the ectoderm.

The general structure of teeth is similar across the vertebrates, although there is considerable variation in their form and position. The teeth of mammals have deep roots, and this pattern is also found in some fish, and in crocodilians. In most teleost fish, however, the teeth are attached to the outer surface of the bone, while in lizards they are attached to the inner surface of the jaw by one side. In cartilaginous fish, such as sharks, the teeth are attached by tough ligaments to the hoops of cartilage that form the jaw.

Some animals develop only one set of teeth (monophyodont) while others develop many sets (polyphyodont). Sharks, for example, grow a new set of teeth every two weeks to replace worn teeth. Rodent incisors grow and wear away continually through gnawing, which helps maintain relatively constant length. The industry of the beaver is due in part to this qualification. Many rodents such as voles and guinea pigs, but not mice, as well as leporidae like rabbits, have continuously growing molars in addition to incisors.

Teeth are not always attached to the jaw, as they are in mammals. In many reptiles and fish, teeth are attached to the palate or to the floor of the mouth, forming additional rows inside those on the jaws proper. Some teleosts even have teeth in the pharynx. While not true teeth in the usual sense, the dermal denticles of sharks are almost identical in structure, and are likely to have the same evolutionary origin. Indeed, teeth appear to have first evolved in sharks, and are not found in the more primitive jawless fish - while lampreys do have tooth-like structures on the tongue, these are in fact, composed of keratin, not of dentine or enamel, and bear no relationship to true teeth. Though "modern" teeth-like structures with dentine and enamel have been found in late conodonts, they are now supposed to have evolved independently of later vertebrates' teeth.

Living amphibians typically have small teeth, or none at all, since they commonly feed only on soft foods. In reptiles, teeth are generally simple and conical in shape, although there is some variation between species, most notably the venom-injecting fangs of snakes. The pattern of incisors, canines, premolars and molars is found only in mammals, and to varying extents, in their evolutionary ancestors. The numbers of these types of teeth varies greatly between species; zoologists use a standardised dental formula to describe the precise pattern in any given group.

A tooth (plural teeth) is a small, calcified, whitish structure found in the jaws (or mouths) of many vertebrates.

Tooth or Teeth may also refer to:

• Human tooth for teeth in humans
• Egg tooth, used by hatchlings to break through an eggshell
• Teething, the process by which an infant's teeth sequentially appear by breaking through the gums
• Teeth (band), a Filipino rock band
• Teeth (film), a 2007 comedy horror film
• "Teeth", a song by Lady Gaga from her EP The Fame Monster
• Teeth, a 1998 novel by Hugh Gallagher (humorist)
• "Teeth", a song by Cage the Elephant from Melophobia
• "Teeth", a song by Fireworks from their 2011 album Gospel