isomer

noun

iso·​mer ˈī-sə-mər How to pronounce isomer (audio)
1
: one of two or more compounds, radicals, or ions that contain the same number of atoms of the same elements but differ in structural arrangement and properties
2
: a nuclide isomeric with one or more others

Examples of isomer in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
This is possible since both Delta 8 is technically an isomer of CBD. — Amber Smith, Discover Magazine, 3 Apr. 2024 The resulting compound includes non-natural THC isomers generated during the hydrogenation process. — Dario Sabaghi, Forbes, 20 Feb. 2024

Word History

Etymology

International Scientific Vocabulary, back-formation from isomeric

First Known Use

1855, in the meaning defined at sense 1

Time Traveler
The first known use of isomer was in 1855

Phrases Containing isomer

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isomagnetic
isomer
isomerase
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Cite this Entry

“Isomer.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/isomer. Accessed 8 Apr. 2025.

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Kids Definition

isomer

noun
iso·​mer ˈī-sə-mər How to pronounce isomer (audio)
: one of two or more chemical compounds or groups that have the same numbers of atoms of the same elements but differ in structure
isomeric
ˌī-sə-ˈmer-ik
adjective
isomerism
ī-ˈsäm-ə-ˌriz-əm
noun

Medical Definition

isomer

noun
iso·​mer ˈī-sə-mər How to pronounce isomer (audio)
1
: any of two or more compounds, radicals, or ions that contain the same number of atoms of the same elements but differ in structural arrangement and properties
2
: a nuclide isomeric with one or more others

More from Merriam-Webster on isomer

Britannica.com: Encyclopedia article about isomer

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