<p><strong>Noun</strong></p><ul><li>(Biochemistry):<ul><li>A pyrimidine base, C₄H₅N₃O, that is one of the fundamental components of DNA and RNA, in which it forms a base pair with guanine.</li><li>Carbon dioxide or other carbon compounds that are emitted into the atmosphere and cause rising temperatures.</li><li>A native or inhabitant of Byzantium.</li></ul></li></ul>