<B>trabecula, </B>noun, pl. <B>-lae.</B><DL COMPACT><DD><B> 1. </B>a structure in an animal or plant like a small beam or bar. <DD><B> 2. </B>(Botany.) a projection extending across the cell cavity in the ducts of some plants, or across the cavity of the sporangium in mosses. </DL>
<A NAME="trabecular">
<B>trabecular, </B>adjective.<DL COMPACT><DD><B> 1. </B>of or having to do with a trabecula. <DD><B> 2. </B>forming or formed by trabeculae. </DL>
<A NAME="trabeculate">
<B>trabeculate, </B>adjective.<DL COMPACT><DD> having a trabecula or trabeculae. </DL>
<A NAME="trace">
<B>trace</B> (1), noun, adjective, verb, <B>traced,</B> <B>tracing.</B><DL COMPACT><DD><I>noun </I> <B>1. </B>a mark or sign of the former existence, presence, or action of something; vestige. <BR> <I>Ex. The explorers found traces of an ancient city (Figurative.) In countries where all trace of the limited monarchy of the middle ages had long been effaced (Macaulay).</I> <DD><B> 2a. </B>a footprint or other mark left by the passage of a person, animal, or thing; track. <BR> <I>Ex. We saw traces of rabbits and squirrels on the snow.</I> <DD><B> b. </B>a beaten path, as through a wild region; trail; track. <BR> <I>Ex. the Natchez Trace.</I> <DD><B> 3. </B>(Figurative.) a very small amount; little bit. <BR> <I>Ex. There was not a trace of color in her cheeks. The trace of rainfall in the desert is too small to be measured.</I> <DD><B> 4a. </B>a line or figure marked out or drawn; tracing, drawing, or sketch of something. <DD><B> b. </B>the line made by a self-recording instrument such as a cardiograph or seismograph. <DD><B> 5. </B>(Chemistry.) an indication of an amount of some constituent in a compound, usually too small to be measured. <DD><B> 6. </B>(Psychology.) an engram. <DD><B> 7. </B>(Obsolete.) the way or path which anything takes. <DD><I>adj. </I> (Chemistry.) consisting of a trace; too small to be measured. <BR> <I>Ex. a chemical found in trace amounts in the body. Uranium is the most highly concentrated trace metal found in the miners' lungs (Franklin J. Tobey, Jr.).</I> <DD> See <B>trace element.</B> <DD><I>v.t. </I> <B>1. </B>to follow by means of marks, tracks, or signs. <BR> <I>Ex. to trace deer. The dog traced the fox to its den. The counterfeit money was traced to a foreign printer.</I> <DD><B> 2. </B>(Figurative.) to follow the course, development, or history of. <BR> <I>Ex. to trace the meanings of a word. He traced the river to its source. The Aldens trace their family back three hundred years to John Alden, one of the Pilgrims.</I> <DD><B> 3. </B>(Figurative.) to find signs or proof of; observe; discover. <BR> <I>Ex. I could never trace in her one spark of jealousy (Robert Louis Stevenson).</I> <DD><B> 4. </B>to draw an outline of; mark out; draw; sketch. <BR> <I>Ex. The spy traced a plan of the fort.</I> <DD><B> 5. </B>to copy by following the lines of with a pencil or pen. <BR> <I>Ex. He put thin paper over the map and traced it.</I> <DD><B> 6. </B>to decorate with tracery. <DD><B> 7. </B>towrite, especially by forming the letters carefully or laboriously. <BR> <I>Ex. The old man seized the pen and traced his name (Francis M. Crawford).</I> <DD><B> 8. </B>to copy, impress, or imprint with a tracer. <DD><B> 9. </B>to record in the form of a curving, wavy, or broken line, as a cardiograph or seismograph does. <DD><B> 10. </B>(Obsolete.) to pass along or over; traverse. <DD><I>v.i. </I> <B>1. </B>to trace the origin or history of something; go back in time. <DD><B> 2. </B>(Obsolete.) to make one's way; go; proceed; travel. </DL>
<A NAME="trace">
<B>trace</B> (2), noun.<DL COMPACT><DD><B> 1. </B>either of the two straps, ropes or chains by which an animal pulls a wagon, carriage, or other vehicle. <DD><B> 2. </B><B>=connecting rod.</B> <BR><I>expr. <B>kick over the traces,</B> </I>to throw off controls or restraints; become unruly. <BR> <I>Ex. I could not help thinking that Mr. Finney might produce something really worth listening to if he could kick over the traces of the serial system of composition (New Yorker).</I> </DL>
<A NAME="traceability">
<B>traceability, </B>noun.<DL COMPACT><DD> the fact or property of being traceable. </DL>
<A NAME="traceable">
<B>traceable, </B>adjective.<DL COMPACT><DD><B> 1. </B>that can be traced. <DD><B> 2. </B>(Figurative.) attributable. <BR> <I>Ex. The engine's failure was traceable to an oil leak.</I> noun <B>traceableness.</B> adv. <B>traceably.</B> </DL>
<A NAME="traceelement">
<B>trace element,</B><DL COMPACT><DD> a chemical element, especially a metallic one, used in small amounts by an organism but considered necessary to the organism's proper functioning; minor element. The trace elements include copper, cobalt, magnesium, manganese, and zinc. </DL>
<A NAME="traceless">
<B>traceless, </B>adjective.<DL COMPACT><DD> leaving or showing no traces. adv. <B>tracelessly.</B> </DL>
<A NAME="tracer">
<B>tracer, </B>noun.<DL COMPACT><DD><B> 1. </B>a person or thing that traces, especially a person whose business is tracing missing persons or property. <DD><B> 2. </B>a machine for making tracings, as of drawings and plans. <DD><B> 3. </B>an inquiry sent from place to place to trace a missing person, article, letter, parcel, or other lost item. <BR> <I>Ex. We'll put out a tracer on your stolen car.</I> <DD><B> 4a. </B>a burning substance put in a tracer bullet to show its course. <DD><B> b. </B><B>=tracer bullet.</B> <DD><B> 5. </B>(Chemistry.) an element or atom, usually radioactive, that can be traced and observed as it passes through a body, plant, or other system in order to study biological processes or chemical reactions within the system. </DL>
<A NAME="tracerbullet">
<B>tracer bullet,</B><DL COMPACT><DD><B> 1. </B>a bullet with a substance in it that burns when the bullet is fired, leaving a trail that can be followed with the eye. <DD><B> 2. </B>a shell containing such a substance. </DL>
<A NAME="traceried">
<B>traceried, </B>adjective.<DL COMPACT><DD> ornamented with tracery. <BR> <I>Ex. a traceried window.</I> </DL>
<A NAME="tracery">
<B>tracery, </B>noun, pl. <B>-eries.</B><DL COMPACT><DD><B> 1. </B>ornamental work or designs consisting of very fine lines, as in certain kinds of embroidery. <DD><B> 2. </B>a pattern of intersecting bars or a plate with leaflike decorations in the upper part of a Gothic window, in the ribs of a vault, in carved panels, and in plasterwork. </DL>
<A NAME="trachea">
<B>trachea, </B>noun, pl. <B>tracheae,</B> <B>tracheas.</B><DL COMPACT><DD><B> 1. </B>the tube in airbreathing vertebrates extending from the larynx to the bronchi, by which air is carried to and from the lungs; windpipe. <DD><B> 2. </B>(Zoology.) one of the air-carrying tubes of the respiratory system of insects and other arthropods. <DD><B> 3. </B>(Botany.) <DD><B> a. </B>a duct in the xylem of a vascular plant, formed by a row of cells (tracheids) that have lost their intervening partitions and have become a single long canal permitting the passage of water and dissolved minerals. Tracheae are covered with various markings or thickenings, the spiral being the common type. <DD><B> b. </B>one of these cells. </DL>
<A NAME="tracheal">
<B>tracheal, </B>adjective.<DL COMPACT><DD> of or having to do with the trachea. </DL>
<A NAME="tracheary">
<B>tracheary, </B>adjective.<DL COMPACT><DD> (Botany.) of or having to do with tracheae or tracheids. </DL>
<A NAME="tracheate">
<B>tracheate, </B>adjective, noun.<DL COMPACT><DD> (Zoology.) <DD><I>adj. </I> having tracheae. <DD><I>noun </I> a tracheate arthropod. </DL>
<A NAME="tracheid">
<B>tracheid, </B>noun.<DL COMPACT><DD> (Botany.) an elongated, more or less lignified cell with thick, perforated walls, that serves to carry water and dissolved minerals through a plant, and provides support. Tracheids form an essential element of the xylem of vascular plants. </DL>
<A NAME="tracheidal">
<B>tracheidal, </B>adjective.<DL COMPACT><DD> of, having to do with, or like tracheids. </DL>
<A NAME="tracheitis">
<B>tracheitis, </B>noun.<DL COMPACT><DD> inflammation of the windpipe. </DL>
<A NAME="tracheobronchial">
<B>tracheobronchial, </B>adjective.<DL COMPACT><DD> having to do with the trachea and the bronchi. </DL>
<A NAME="tracheole">
<B>tracheole, </B>noun.<DL COMPACT><DD> one of the tiny branches of the trachea of an insect. </DL>
<A NAME="tracheoscopic">
<B>tracheoscopic, </B>adjective.<DL COMPACT><DD> of or having to do with tracheoscopy. </DL>
<A NAME="tracheoscopist">
<B>tracheoscopist, </B>noun.<DL COMPACT><DD> a person skilled in tracheoscopy. </DL>
<A NAME="tracheoscopy">
<B>tracheoscopy, </B>noun, pl. <B>-pies.</B><DL COMPACT><DD> examination of the interior of the trachea, as with a laryngoscope. </DL>
<A NAME="tracheotomist">
<B>tracheotomist, </B>noun.<DL COMPACT><DD> a surgeon who performs a tracheotomy. </DL>
<A NAME="tracheotomy">
<B>tracheotomy, </B>noun, pl. <B>-mies.</B><DL COMPACT><DD> surgical incision into the trachea. </DL>
<A NAME="trachle">
<B>trachle, </B>transitive verb, <B>-chled,</B> <B>-chling.</B><DL COMPACT><DD> (Scottish.) <DD><B> 1a. </B>to dishevel. <DD><B> b. </B>to disorder or injure by trampling. <DD><B> 2a. </B>to exhaust. <DD><B> b. </B>(Figurative.) to distress. Also, <B>trauchle.</B> </DL>
<A NAME="trachodon">
<B>trachodon, </B>noun. <B>=trachodont.</B></DL>
<A NAME="trachodont">
<B>trachodont, </B>noun.<DL COMPACT><DD> a very large dinosaur with a broad, flat skull, lower jaws like a duck's bill, and as many as 2,000 teeth. Some kinds had webbed feet. </DL>
<A NAME="trachoma">
<B>trachoma, </B>noun.<DL COMPACT><DD> a contagious inflammation of the mucous membrane of the eyeball and eyelids, caused by a virus. Trachoma is common in the Orient and sometimes causes blindness. </DL>
<A NAME="trachomatous">
<B>trachomatous, </B>adjective.<DL COMPACT><DD> of or affected with trachoma. </DL>
<A NAME="trachyte">
<B>trachyte, </B>noun.<DL COMPACT><DD> a light, volcanic rock with a rough surface, consisting of feldspars and augite or biotite. </DL>
<A NAME="trachytic">
<B>trachytic, </B>adjective.<DL COMPACT><DD> (of rock) having densely packed prisms of feldspar lying parallel to each other. </DL>
<A NAME="tracing">
<B>tracing, </B>noun.<DL COMPACT><DD><B> 1. </B>a copy of something made by putting thin paper over it and following the lines of it with a pencil or pen. <DD><B> 2. </B>a line made by marking or drawing. <DD><B> 3. </B>one of a series of lines or marks made by an electrical apparatus, such as a lie detector, electrocardiograph, or electroencephalograph, that records waves or impulses. </DL>
<A NAME="tracingpaper">
<B>tracing paper,</B><DL COMPACT><DD> a thin, almost transparent paper for tracing or copying an original design. </DL>
