| aconitic acid | <chemical> Chemical name: 1-Propene-1,2,3-tricarboxylic acid (12 Dec 1998) |
|---|---|
| aconitine | <chemistry> An intensely poisonous alkaloid, extracted from aconite. Source: Websters Dictionary (01 Mar 1998) |
| acontia | 1. <zoology> Threadlike defensive organs, composed largely of nettling cells (cnidae), thrown out of the mouth or special pores of certain Actiniae when irritated. 2. <zoology> Anciently, a snake, called dart snake; now, one of a genus of reptiles closely allied to the lizards. Origin: NL, from Gr. A little dart. Source: Websters Dictionary (01 Mar 1998) |
| acopic | <medicine> Relieving weariness; restorative. Origin: Gr. Priv. + striking. Weariness, to strike. Source: Websters Dictionary (01 Mar 1998) |
| acorea | Congenital absence of the pupil of the eye. Origin: G. A-priv. + kore, pupil (05 Mar 2000) |
| acorn | 1. <botany> The fruit of the oak, being an oval nut growing in a woody cup or cupule. 2. A cone-shaped piece of wood on the point of the spindle above the vane, on the mast-head. Origin: AS. Aecern, fr. Aecer field, acre; akin to D. Aker acorn, Ger. Ecker, Icel. Akarn, Dan. Agern, Goth. Akran fruit, akrs field; orig. Fruit of the field. Source: Websters Dictionary (01 Mar 1998) |
| acorn-shell | <zoology> One of the sessile cirripeds; a barnacle of the genus Balanus. Source: Websters Dictionary (01 Mar 1998) |
| acorn-tipped catheter | A catheter used in ureteropyelography to occlude the ureteral orifice and prevent backflow from the ureter during and following the injection of an opaque medium. (05 Mar 2000) |
| Acosta's disease | A condition that results from prolonged exposure to high altitude. Symptoms include a continuous dry cough, shortness of breath, poor exercise tolerance, dizziness, headache, sleep difficulty, anorexia, confusion, fatigue and a rapid pulse. Treatment includes the immediate movement to a lower altitude. Prophylaxis has been accomplished successfully with the use of acetazolamide (Diamox). (27 Sep 1997) |
| Acosta, Joseph de | <person> Spanish Jesuit missionary, 1539-1600. See: Acosta's disease. (05 Mar 2000) |
| acotyledon | <botany> A plant which has no cotyledons, as the dodder and all flowerless plants. See: Cotyledon. Origin: Gr. Priv. + anything cup-shaped. Source: Websters Dictionary (01 Mar 1998) |
| acotyledonous | <botany> Having no seed lobes, as the dodder; also applied to plants which have no true seeds, as ferns, mosses, etc. Source: Websters Dictionary (01 Mar 1998) |
| acouasm | Rarely used term for an auditory hallucination in which indefinite sounds, such as ringing or hissing, are heard. Synonym: acouasm. Origin: G. Akousma, something heard (05 Mar 2000) |
| acouchy | <zoology> A small species of agouti (Dasyprocta acouchy). Origin: F. Acouchi, from the native name Guiana. Source: Websters Dictionary (01 Mar 1998) |
| acoumeter | <physics> An instrument for measuring the acuteness of the sense of hearing. Origin: Gr. To hear. Source: Websters Dictionary (01 Mar 1998) |