tau·​to·​mer ˈtȯ-tə-mər How to pronounce tautomer (audio)
: any of the forms of a tautomeric compound

Examples of tautomer in a Sentence

Recent Examples on the Web Such an altered base pair, known as a tautomer, can quickly jump back to its original arrangement. Lars Fischer, Scientific American, 18 Aug. 2022 Called a tautomer, the drug assumes two forms, one which closely resembles uracil (U) and the other cytosine (C). William A. Haseltine, Forbes, 8 Oct. 2021

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'tautomer.' 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, from tautomeric

First Known Use

1898, in the meaning defined above

Time Traveler
The first known use of tautomer was in 1898

Dictionary Entries Near tautomer

Cite this Entry

“Tautomer.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/tautomer. Accessed 26 Sep. 2023.

Medical Definition


tau·​to·​mer ˈtȯt-ə-mər How to pronounce tautomer (audio)
: any of the forms of a tautomeric compound
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