| trace | 1. To mark out; to draw or delineate with marks; especially, to copy, as a drawing or engraving, by following the lines and marking them on a sheet superimposed, through which they appear; as, to trace a figure or an outline; a traced drawing. "Some faintly traced features or outline of the mother and the child, slowly lading into the twilight of the woods." (Hawthorne) 2. To follow by some mark that has been left by a person or thing which has preceded; to follow by footsteps, tracks, or tokens. "You may trace the deluge quite round the globe." (T. Burnet) "I feel thy power . . . To trace the ways Of highest agents." (Milton) 3. Hence, to follow the trace or track of. "How all the way the prince on footpace traced." (Spenser) 4. To copy; to imitate. "That servile path thou nobly dost decline, Of tracing word, and line by line." (Denham) 5. To walk over; to pass through; to traverse. "We do tracethis alley up and down." (Shak) Origin: OF. Tracier, F. Tracer, from (assumed) LL. Tractiare, fr.L. Tractus, p. P. Of trahere to draw. Cf. Abstract, Attract, Contract, Portratt, Tract, Trail, Train, Treat. 1. A mark left by anything passing; a track; a path; a course; a footprint; a vestige; as, the trace of a carriage or sled; the trace of a deer; a sinuous trace. 2. <chemistry> A very small quantity of an element or compound in a given substance, especially when so small that the amount is not quantitatively determined in an analysis;-hence, in stating an analysis, often contracted to tr. 3. A mark, impression, or visible appearance of anything left when the thing itself no longer exists; remains; token; vestige. "The shady empire shall retain no trace Of war or blood, but in the sylvan chase." (Pope) 4. <geometry> The intersection of a plane of projection, or an original plane, with a coordinate plane. 5. The ground plan of a work or works. Syn.-Vestige; mark; token. See Vestige. Origin: F. Trace. See Trace. Source: Websters Dictionary (01 Mar 1998) |
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| trace conditioned reflex | A conditioned reflex established by applying the stimulus a short time before reinforcement; in the conditioned reflex of the animal so prepared, the response occurs at the same interval of time after the application of the stimulus as during the period of training. (05 Mar 2000) |
| trace conditioning | Conditioning when there is no temporal overlap between the conditioning stimulus and the unconditioned stimulus. (05 Mar 2000) |
| trace element | Any chemical element that an organism needs very small quantities of tosurvive. (09 Oct 1997) |
| trace elements | A group of chemical elements that are needed in minute quantities for the proper growth, development, and physiology of an organism. (12 Dec 1998) |
| trace nutrient | Essential dietary elements required only in small quantities. They are present in the body in amounts less than .005% of body weight. (12 Dec 1998) |
| tracer | 1. An element or compound containing atoms that can be distinguished from their normal counterparts by physical means (e.g., radioactivity assay or mass spectrography) and can thus be used to follow (trace) the metabolism of the normal substances. 2. A coloured substance (e.g., a dye) used as a tracer to follow the flow of water. 3. An instrument used in dissecting out nerves and blood vessels. 4. A mechanical device with a marking point attached to one jaw and a graph plate or tracing plate attached to the other jaw; used to record the direction and extent of movements of the mandible. See: tracing. Origin: M.E. Track, fr. O. Fr. Tracier, to make one's way, fr. L. Traho, pp. Tractum, to draw, + -er, agent suffix (05 Mar 2000) |
| tracer/y | Ornamental work with rambled lines. Especially: The decorative head of a Gothic window. Window tracery is of two sorts, plate tracery and bar tracery. Plate tracery, common in Italy, consists of a series of ornamental patterns cut through a flat plate of stone. Bar tracery is a decorative pattern formed by the curves and intersections of the molded bars of the mullions. Window tracery is imitated in many decorative objects, as panels of wood or metal either pierced or in relief. See also Stump tracery under Stump, and Fan tracery under Fan. A similar decoration in some styles of vaulting, the ribs of the vault giving off the minor bars of which the tracery is composed. Source: Websters Dictionary (01 Mar 1998) |
| memory trace | See: engram. (05 Mar 2000) |
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