| hammer | 1. An instrument for driving nails, beating metals, and the like, consisting of a head, usually of steel or iron, fixed crosswise to a handle. "With busy hammers closing rivets up." (Shak) 2. Something which in firm or action resembles the common hammer; as: That part of a clock which strikes upon the bell to indicate the hour. The padded mallet of a piano, which strikes the wires, to produce the tones. <anatomy> That part of a gunlock which strikes the percussion cap, or firing pin; the cock; formerly, however, a piece of steel covering the pan of a flintlock musket and struck by the flint of the cock to ignite the priming. Also, a person of thing that smites or shatters; as, St. Augustine was the hammer of heresies. "He met the stern legionaries [of Rome] who had been the "massive iron hammers" of the whole earth." (J. H. Newman) Atmospheric hammer, a dead-stroke hammer in which the spring is formed by confined air. Drop hammer, Face hammer, etc. See Drop, Face, etc. Hammer fish. See Hammerhead. Hammer hardening, the process of hardening metal by hammering it when cold. <zoology> Hammer shell, any species of Malleus, a genus of marine bivalve shells, allied to the pearl oysters, having the wings narrow and elongated, so as to give them a hammer-shaped outline; called also hammer oyster. To bring to the hammer, to put up at auction. Origin: OE. Hamer, AS. Hamer, hamor; akin to D. Hamer, G. & Dan. Hammer, Sw. Hammare, Icel. Hamarr, hammer, crag, and perh. To Gr. Anvil, Skr. Aman stone. Source: Websters Dictionary (01 Mar 1998) |
|---|---|
| hammer finger | An avulsion, partial or complete, of the long finger extensor from the base of the distal phalanx. Synonym: drop finger, hammer finger, mallet finger. (05 Mar 2000) |
| hammer nose | A manifestation of severe acne rosacea resulting in significant enlargement of the nose and occurring primarily in men. It is caused by hypertrophy of the sebaceous glands and surrounding connective tissue. The nose is reddened and marked with numerous telangiectasias. (12 Dec 1998) |
| hammer toe | <orthopaedics> A deformity of the toe in which the toe is bent upward like a claw. most commonly seen in the second toe, the condition may be congenital or acquired. Ill fitting shoes (too short or too narrow a fit) can result in hammer toe. Mild cases can be treated with splinting or special shoe inserts. Severe cases may require surgery to straighten the toe. (06 Mar 2000) |
| hammerhead | 1. <zoology> A shark of the genus Sphyrna or Zygaena, having the eyes set on projections from the sides of the head, which gives it a hammer shape. The Sphyrna zygaena is found in the North Atlantic. Called also hammer fish, and balance fish. 2. <zoology> A fresh water fish; the stone-roller. 3. <zoology> An African fruit bat (Hypsignathus monstrosus); so called from its large blunt nozzle. Source: Websters Dictionary (01 Mar 1998) |
| hammerkop | <zoology> A bird of the Heron family; the umber. Source: Websters Dictionary (01 Mar 1998) |
| hammermill | A device consisting of a rotating head with free-swinging hammers which reduce chips or hogged fuel to a predetermined particle size through a perforated screen. (05 Dec 1998) |
| Hammerschlag's method | A hydrometric method of determining the specific gravity of the blood by allowing a drop of blood to fall into each of a series of tubes containing mixtures of chloroform and benzene of known graded specific gravities; the specific gravity of that mixture in which the drop remains exactly suspended, neither rising nor falling, corresponds to the specific gravity of the blood sample. (05 Mar 2000) |
| Hammerschlag, Albert | <person> Austrian physician, 1863-1935. See: Hammerschlag's method. (05 Mar 2000) |
| water hammer | <physics> 1. A vessel partly filled with water, exhausted of air, and hermetically sealed. When reversed or shaken, the water being unimpeded by air, strikes the sides in solid mass with a sound like that of a hammer. 2. A concussion, or blow, made by water in striking, as against the sides of a pipe or vessel containing it. Source: Websters Dictionary (01 Mar 1998) |
|---|---|
| water-hammer pulse | <radiology> Corrigan's sign: increased pulse at wrist, aortic insufficiency, widened pulse pressure due to increased stroke volume, diastolic regurgitation (12 Dec 1998) |