[¦tü ¦fȯr ¦siks trī¦nī·trō′täl·yə‚wēn] (organic chemistry) CH3C6H2(NO2)3 Toxic, flammable, explosive, yellow crystals; soluble in alcohol and ether, insoluble in water; melts at 81°C; used as an explosive and chemical intermediate and in photographic chemicals. Abbreviated TNT.