| sea spider | <zoology> Any maioid crab; a spider crab. See Maioid, and Spider crab, under Spider. Any pycnogonid. Source: Websters Dictionary (01 Mar 1998) |
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| spider | 1. <zoology> Any one of numerous species of arachnids comprising the order Araneina. Spiders have the mandibles converted into poison fangs, or falcers. The abdomen is large and not segmented, with two or three pairs of spinnerets near the end, by means of which they spin threads of silk to form cocoons, or nests, to protect their eggs and young. Many species spin also complex webs to entrap the insects upon which they prey. The eyes are usually eight in number (rarely six), and are situated on the back of the cephalothorax. Spiders are divided into two principal groups: the Dipneumona, having two lungs: and the Tetrapneumona, having four lungs. See Mygale. The former group includes several tribes; as, the jumping spiders (see Saltigradae), the wolf spiders, or Citigradae (see under Wolf), the crab spiders, or Laterigradae (see under Crab), the garden, or geometric, spiders, or Orbitellae (see under Geometrical, and Garden), and others. See Bird spider, Grass spider, House spider, Silk spider. 2. <zoology> Any one of various other arachnids resembling the true spiders, especially certain mites, as the red spider (see under Red). 3. An iron pan with a long handle, used as a kitchen utensil in frying food. Originally, it had long legs, and was used over coals on the hearth. 4. A trevet to support pans or pots over a fire. 5. <machinery> A skeleton, or frame, having radiating arms or members, often connected by crosspieces; as, a casting forming the hub and spokes to which the rim of a fly wheel or large gear is bolted; the body of a piston head; a frame for strengthening a core or mold for a casting, etc. Spider ant. Any one of numerous species of South American monkeys of the genus Ateles, having very long legs and a long prehensile tail. <botany> Spider orchis, any shell of the genus Pteroceras. See Pteroceras. Origin: OE. Spire, fr. AS. Spinnan to spin; so named from spinning its web; cf. D. Spin a spider, G. Spinne, Sw. Spindel. Seee Spin. Source: Websters Dictionary (01 Mar 1998) |
| spider angiomas | A branched growth of dilated capillaries on the skin, resembling a spider. This abnormality may be associated with cirrhosis of the liver. (27 Sep 1997) |
| spider-burst | Radiating dull red capillary lines on the skin of the leg, usually without any visible or palpable varicose veins, but nevertheless due to deep-seated venous dilation; sometimes referred to as skyrocket capillary ectasis. Origin: spiderweb + sunburst (05 Mar 2000) |
| spider cancer | An obsolete term for a malignant neoplasm with a rhizoid or filamentous edge of thin, threadlike, red lines that represent dilated vascular channels associated with the neoplasm; a form of telangiectatic cancer. (05 Mar 2000) |
| spider cell | <pathology> A glial cell found in vertebrate brain, named for its characteristic star like shape. Astrocytes lend both mechanical and metabolic support for neurons, regulating the environment in which they function. See: oligodendrocytes. (18 Nov 1997) |
| spider finger | <clinical sign> A skeletal disorder where the patient has unusually long, thin bones, especially noticeable in the fingers and toes. (09 Oct 1997) |
| spider haemangioma | spider angioma |
| spider mole | spider angioma |
| spider nevus | A branched growth of dilated capillaries on the skin, resembling a spider. This abnormality may be associated with cirrhosis of the liver. (27 Sep 1997) |
| spider pelvis | Narrow calices of renal pelvis. (05 Mar 2000) |
| spider's web | <zoology> The silken web which is formed by most kinds of spiders, particularly the web spun to entrap their prey. See Geometric spider, Triangle spider, under Geometric, and Triangle. Source: Websters Dictionary (01 Mar 1998) |
| spider telangiectasia | spider angioma |
| spider venoms | Venoms of arthropods of the order araneida of the arachnida. The venoms usually contain several protein fractions, including enzymes, haemolytic, neurolytic, and other toxins. (12 Dec 1998) |