Definition of thymine in English:



mass nounBiochemistry
  • A compound which is one of the four constituent bases of nucleic acids. A pyrimidine derivative, it is paired with adenine in double-stranded DNA.

    Alternative name; 5-methyluracil; chemical formula: C₅H₆N₂O₂

    • ‘Of the four bases that make up DNA - adenine, thymine, cytosine and guanine - only cytosine has the potential to be methylated in humans and most mammals.’
    • ‘The nitrogen-containing bases are adenine, thymine, cytosine, and guanine; these names are used to identify the nucleotides.’
    • ‘The film's name comes from the initials of the four DNA bases of our genetic code: guanine, adenine, cytosine and thymine.’
    • ‘In DNA the bases pair to form a ladder-like structure, with adenine paired with thymine and guanine with cytosine.’
    • ‘The derivatives of purine are called adenine and guanine, and the derivatives of pyrimidine are called thymine, cytosine and uracil.’


Late 19th century: from thymus + -ine.