<B>thiol, </B>noun.<DL COMPACT><DD><B> 1. </B>any organic compound of a series resembling the alcohols and phenols, but containing sulfur in place of oxygen; mercaptan. <DD><B> 2. </B>the univalent radical -SH; sulfhydryl. </DL>
<A NAME="thiolaceticacid">
thiolacetic acid, =thioacetic acid.</DL>
<A NAME="thionate">
<B>thionate, </B>noun.<DL COMPACT><DD> a salt or ester of a thionic acid. </DL>
<A NAME="thionic">
<B>thionic, </B>adjective.<DL COMPACT><DD> (Chemistry.) <DD><B> 1. </B>of or containing sulfur. <DD><B> 2. </B>having oxygen replaced by sulfur. </DL>
<A NAME="thionin">
<B>thionin, </B>noun. =thionine.</DL>
<A NAME="thionine">
<B>thionine, </B>noun.<DL COMPACT><DD><B> 1. </B>a dark crystalline, basic compound derived from thiazine, used as a violet stain in microscopy. <DD><B> 2. </B>any of several allied dyes. </DL>
<A NAME="thionyl">
<B>thionyl, </B>noun.<DL COMPACT><DD> a bivalent inorganic radical -SO; sulfinyl. </DL>
<A NAME="thiopentalsodium">
<B>thiopental sodium,</B><DL COMPACT><DD> a yellowish-white barbiturate similar to pentobarbital sodium, used as an anesthetic; Pentothal Sodium; sodium pentothal. </DL>
<B>thiophene, </B>noun.<DL COMPACT><DD> a colorless liquid compound, present in coal tar, with an odor like that of benzene, and with properties similar to those of benzene. </DL>
<A NAME="thiophenol">
<B>thiophenol, </B>noun.<DL COMPACT><DD> a colorless mobile liquid with the odor of garlic, regarded as phenol with the oxygen replaced by sulfur. </DL>
<A NAME="thiophosphate">
<B>thiophosphate, </B>noun.<DL COMPACT><DD> a salt or ester of thiophosphoric acid. </DL>
<A NAME="thiophosphoricacid">
<B>thiophosphoric acid,</B><DL COMPACT><DD> an acid produced from phosphoric acid by replacing one or more oxygen atoms with an atom of sulfur. </DL>
<A NAME="thioridazine">
<B>thioridazine, </B>noun.<DL COMPACT><DD> a drug used as a tranquilizer, especially in the treatment of schizophrenia and senility. </DL>
<A NAME="thiosemicarbazone">
<B>thiosemicarbazone, </B>noun.<DL COMPACT><DD> a toxic, pale-yellow, crystalline compound, used in treating leprosy and pulmonary tuberculosis. </DL>
<A NAME="thiosinamine">
<B>thiosinamine, </B>noun.<DL COMPACT><DD> a colorless crystalline compound having a garlicky odor, produced by heating mustard oil and alcohol with ammonia. It is used in medicine and in photography. </DL>
<A NAME="thiosulfate">
<B>thiosulfate, </B>noun.<DL COMPACT><DD> a salt or ester of thiosulfuric acid. </DL>
<A NAME="thiosulfuricacid">
<B>thiosulfuric acid,</B><DL COMPACT><DD> an unstable acid, considered as sulfuric acid in which one atom of oxygen is replaced by sulfur. It occurs only in solution or in the form of its salts (thiosulfates). </DL>
<A NAME="thiotepa">
<B>thioTEPA</B> or <B>thiotepa, </B>noun.<DL COMPACT><DD> a crystalline drug derived from nitrogen mustard, used in arresting the growth of cancerous tissue by inhibiting cell division, as in the alleviation of leukemia. </DL>
<A NAME="thiouracil">
<B>thiouracil, </B>noun.<DL COMPACT><DD> a white crystalline powder used in treating hyperthyroidism. </DL>
<A NAME="thiourea">
<B>thiourea, </B>noun.<DL COMPACT><DD> a bitter, colorless crystalline substance, considered as urea with sulfur substituted for the oxygen; thiocarbamide. It is used especially in photography. </DL>
<B>thiram, </B>noun.<DL COMPACT><DD> a white crystalline compound used as a fungicide, seed disinfectant, and bacteriostat. </DL>
<A NAME="third">
<B>third, </B>adjective, noun, verb.<DL COMPACT><DD><I>adj. </I> <B>1. </B>next after the second; last in a series of three. <BR> <I>Ex. C is the third letter of the alphabet.</I> <DD><B> 2. </B>being one of three equal parts. <DD><B> 3. </B>(U.S.) of, having to do with, or designating the gear used for ordinary driving in an automobile with a standard transmission; high. <BR> <I>Ex. to shift into third gear.</I> <DD><I>noun </I> <B>1. </B>the next after the second; last in a series of three. <DD><B> 2. </B>one of three equal parts into which a unit or total may be divided. <BR> <I>Ex. Mother divided the cake into thirds.</I> <DD><B> 3. </B>the third of the subdivisions of any standard measure or dimension that is successively subdivided in a constant ratio; subdivision next below seconds. <DD><B> 4. </B>(Music.) <DD><B> a. </B>a tone or note three diatonic degrees from a given tone or note. <DD><B> b. </B>the interval of two tones between such tones or notes. <DD><B> c. </B>the harmonic combination of such tones or notes. <DD><B> d. </B>the third tone or note of a scale, three diatonic degrees above the tonic; mediant. <DD><B> 5. </B>(U.S.) third gear; high. <DD><I>v.t. </I> <B>1. </B>to divide (anything) into three equal parts; reduce to one third the number or bulk. <DD><B> 2. </B>to speak in favor of (a motion, proposition, or the like) as third speaker; support the seconder. <BR> <I>Ex. A motion of the lord Wharton, seconded and thirded by the lords Somers and Halifax (N. Luttrell).</I> <BR>expr. <B>thirds,</B> <DD><B> a. </B>one third of the property of a deceased husband, to which the widow is entitled if there is a child or children. <DD><B> b. </B>a widow's dower. </DL>
<A NAME="thirdbase">
<B>third base,</B><DL COMPACT><DD> (Baseball.) <DD><B> 1. </B>the base that must be touched third by a runner. <DD><B> 2. </B>the position of the fielder covering the area near this base. </DL>
<A NAME="thirdborough">
<B>thirdborough, </B>noun.<DL COMPACT><DD> formerly in England: <DD><B> 1. </B>the head of a frankpledge or tithing. <DD><B> 2. </B>the peace officer of a tithing; petty constable of a township or manor. </DL>
<A NAME="thirdclass">
<B>third class,</B><DL COMPACT><DD><B> 1a. </B>the lowest or next to the lowest class of accommodations on any one of various railroads in Europe, Great Britain, and elsewhere. <DD><B> b. </B>(formerly) the lowest class of accommodations on a passenger vessel; tourist class. <DD><B> 2. </B>a class of mail consisting of printed matter other than newspapers or periodicals, usually not sealed and weighing less than 16 ounces. <DD><B> 3. </B>(Especially British.) <DD><B> a. </B>the class next below the second in an examination list. <DD><B> b. </B>a place in this class. </DL>
<A NAME="thirdclass">
<B>third-class, </B>adjective, adverb.<DL COMPACT><DD><I>adj. </I> <B>1. </B>of or belonging to a class after the second. <DD><B> 2. </B>of or having to do with third class. <DD><B> 3. </B>of distinctly inferior quality; third-rate. <DD><I>adv. </I> in or by a third-class conveyance or accommodations. <BR> <I>Ex. to travel third-class.</I> </DL>
<A NAME="thirdclassmatter">
<B>third-class matter,</B><DL COMPACT><DD> (in the postal system of the United States) printed matter other than newspapers or periodicals, sent through the mails by the publishers at special rates. </DL>
<A NAME="thirddegree">
<B>third degree,</B><DL COMPACT><DD><B> 1. </B>(Informal.) the use of severe treatment by the police to force a person to give information or make a confession. <DD><B> 2. </B>the degree of master mason in Freemasonry. </DL>
<A NAME="thirddegreeburn">
<B>third-degree burn,</B><DL COMPACT><DD> a deep burn, with charring and actual destruction of the skin and tissue. </DL>
<A NAME="thirddimension">
<B>third dimension,</B><DL COMPACT><DD><B> 1. </B>the dimension of depth or thickness in a figure, object, or system. <DD><B> 2. </B>(Figurative.) a quality that gives solidity or depth to anything; three-dimensional quality. <BR> <I>Ex. ... music's third dimension--the expression of human drama by means of sound (New Yorker).</I> </DL>
<A NAME="thirddimensional">
<B>third-dimensional, </B>adjective.<DL COMPACT><DD> having depth, as well as length and width; three-dimensional. <BR> <I>Ex. The mural is slightly curved, there is a balustrade and the lighting is so deftly placed that the effect is third-dimensional (New York Times).</I> </DL>
<A NAME="thirdestate">
<B>third estate</B> or <B>Third Estate,</B><DL COMPACT><DD> persons not in the nobility or clergy, especially in French history; common people. </DL>
<A NAME="thirdeyelid">
<B>third eyelid,</B> =nictitating membrane.</DL>
<A NAME="thirdforce">
<B>third force,</B><DL COMPACT><DD> any person or group that tries to hold a middle course between extreme factions, especially a political group trying to hold such a position. <BR> <I>Ex. New York's Liberal Party--a powerful third force in New York politics (Time).</I> </DL>
<A NAME="thirdhand">
<B>third-hand, </B>adjective, adverb.<DL COMPACT><DD><I>adj. </I> <B>1. </B>obtained, copied, or imitated from a second-hand source; further away from the original source, and so more stale, less authoritative, etc., than the second-hand source. <BR> <I>Ex. Second-hand and third-hand opinions and views ... are buzzing around this camp like flies (J. D. Salinger).</I> <DD><B> 2. </B>dealing in third-hand goods. <DD><I>adv. </I> from a source twice removed from the original. <BR> <I>Ex. Details from a Canadian reporter's first-hand description of a royal tour turn up third-hand in a biography (Maclean's).</I> </DL>
<A NAME="thirdhouse">
<B>Third House,</B><DL COMPACT><DD> (U.S.) a body of lobbyists; group that tries to influence legislators. <BR> <I>Ex. And the power of the so-called "Third House"--the special interest lobbies that had long ruled Sacramento--was waning (Harper's).</I> </DL>
<A NAME="thirdinternational">
<B>Third International,</B><DL COMPACT><DD> an organization formed by the Communist Party in Moscow in 1919 to promote communism outside Russia; Communist International; Comintern. It was officially dissolved in 1943. </DL>
<A NAME="thirdly">
<B>thirdly, </B>adverb.<DL COMPACT><DD> in the third place. </DL>
<A NAME="thirdmarket">
<B>third market,</B><DL COMPACT><DD> (U.S.) the market in listed stocks not traded on a stock exchange; over-the-counter trading in listed stocks, as distinguished from trading on a national exchange or in unlisted stocks. <BR> <I>Ex. the so-called third market, where brokers arrange private trades of listed stocks (Time).</I> </DL>
<A NAME="thirdorder">
<B>third order</B> or <B>Third Order,</B><DL COMPACT><DD> an order or rule of the Roman Catholic Church that is made up of lay associates of a monastic order, such as the Dominicans or Carmelites; any order of tertiaries. </DL>
