URACIL Meaning of URACIL in English [ 'jʊərəsɪl ]■ noun Biochemistry a compound found in living tissue as a constituent base of RNA (and replaced by thymine in DNA).OriginC19: from ur(ea) + ac(etic) + -il . Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004