| 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) |
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| 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) |
| 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) |
| Bell's palsy | A condition that involves the facial nerve (VII cranial nerve) and results in the paralysis of one side of the face. Bell's (facial nerve palsy) can be differentiated from a central (stroke) deficit by the inability to raise the eyebrow on the affected side. (27 Sep 1997) |
| birth palsy | Indefinite term for any motor abnormality in the infant caused by or attributed to the birthing process; includes obstetrical paralysis, infantile hemiplegia, etc. Synonym: infantile hemiplegia. (05 Mar 2000) |
| brachial birth palsy | Paralysis of the infant's arm due to injury received at birth usually resulting from a shoulder dystocia; three types are recognised: 1) whole arm; 2) upper arm (Erb's p.); 3) forearm (Klumpke's paralysis). (05 Mar 2000) |
| bulbar palsy | Progressive weakness and atrophy of the muscles of the tongue, lips, palate, pharynx, and larynx, usually occurring in later life; most often caused by motor neuron disease. Synonym: bulbar palsy, bulbar paralysis, Duchenne's disease, Erb disease, glossolabiolaryngeal paralysis, glossolabiopharyngeal paralysis. (05 Mar 2000) |
| palsy | <neurology> Complete paralysis. (16 Dec 1997) |
| cerebral palsy | A persisting qualitative motor disorder appearing before the age of three years, due to nonprogressive damage to the brain. (12 Dec 1998) |
| wasting palsy | A serious neurologic disease that results from the progressive degeneration of the motor neurons. (27 Sep 1997) |
| craft palsy | Professional neurosis, a disorder of a group of muscles used chiefly in one's occupation, marked by the occurrence of spasm, paresis, or incoordination on attempt to repeat the habitual movements; e.g., writer's cramp; probably a focal dystonia. Synonym: craft palsy, functional spasm. (05 Mar 2000) |
| creeping palsy | A serious neurologic disease that results from the progressive degeneration of the motor neurons. (27 Sep 1997) |