any of a group of chemical compounds of which pyrimidine is the base, including uracil, thymine and cytosine, which are constituents of nucleic acids and nucleotides, pyrimidine - a heterocyclic 6 membered ring, planar and aromatic in character. The parent compound of the pyrimidine bases of nucleic acid., heterotsüklilise pürimidiini aluselised derivaadid, millest uratsiil, tsütosiin ja tümiin kuuluvad nukleiinhapete koostisse