py·​rim·​i·​dine pī-ˈri-mə-ˌdēn How to pronounce pyrimidine (audio)
: a feeble organic base C4H4N2 of penetrating odor
: a derivative of pyrimidine
especially : a base (such as cytosine, thymine, or uracil) that is a constituent of DNA or RNA

Examples of pyrimidine in a Sentence

Recent Examples on the Web Frozen in ice under ultraviolet radiation, high vacuum and low temperature, the pyrimidine turned into uracil, cytosine and thymine, major components of earthly DNA and RNA. Sidney Perkowitz, Discover Magazine, 19 June 2017 The radiation and harsh temperatures broke down pyrimidine in the ice and formed new compounds related to life, such as uracil and cytosine. Sidney Perkowitz, Discover Magazine, 19 June 2017

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'pyrimidine.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


International Scientific Vocabulary, alteration of pyridine

First Known Use

1885, in the meaning defined at sense 1

Time Traveler
The first known use of pyrimidine was in 1885

Dictionary Entries Near pyrimidine

Cite this Entry

“Pyrimidine.” Dictionary, Merriam-Webster, Accessed 15 Jun. 2024.

Kids Definition


py·​rim·​i·​dine pī-ˈrim-ə-ˌdēn How to pronounce pyrimidine (audio)
: any of a group of bases including several (as cytosine and thymine) that are important parts of DNA or RNA

Medical Definition


py·​rim·​i·​dine pī-ˈrim-ə-ˌdēn, pə- How to pronounce pyrimidine (audio)
: a weakly basic organic compound C4H2N2 of penetrating odor that is composed of a single six-membered ring having four carbon atoms with nitrogen atoms in positions one and three
: a derivative of pyrimidine having its characteristic ring structure
especially : a base (as cytosine, thymine, or uracil) that is a constituent of DNA or RNA

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