pyrimidine

UK: /paɪˈrɪmɪˌdiːn/

US: (pī rim′i dēn′, pi-, pir′ə mi dēn′, -din)

WordReference Random House Unabridged Dictionary of American English © 2026

py•rim•i•dine  (pī rim′i dēn′, pi-, pir′ə mi dēn′, -din), n. [Biochem.]

1. Biochemistry a heterocyclic compound, C₄H₄N₂, that is the basis of several important biochemical substances.
2. Biochemistry one of several pyrimidine derivatives, esp. the bases cytosine, thymine, and uracil, which are fundamental constituents of nucleic acids.

• blend of, blended pyridine and imide 1880–85

Collins Concise English Dictionary © HarperCollins Publishers::

pyrimidine / paɪˈrɪmɪˌdiːn/ noun

1. a liquid or crystalline organic compound with a penetrating odour; 1,3-diazine. It is a weakly basic soluble heterocyclic compound and can be prepared from barbituric acid. Formula: C₄H₄N₂
2. Also called: pyrimidine base any of a number of similar compounds having a basic structure that is derived from pyrimidine, including cytosine, thymine, and uracil, which are constituents of nucleic acids

Etymology: 20th Century: variant of pyridine