[′täl·yə‚wēn ¦tü ¦fȯr dī¦ī·sō′sī·ə‚nāt] (organic chemistry) CH3C6H3(NCO)2 A liquid (at room temperature) with a sharp, pungent odor; miscible with ether, acetone, and benzene; used to make polyurethane foams and other elastomers, and also as a protein cross-linking agent.