RNA

noun

ˌär-(ˌ)en-ˈā How to pronounce RNA (audio)
: any of various nucleic acids that contain ribose and uracil as structural components and are associated with the control of cellular chemical activities compare messenger rna, ribosomal rna, transfer rna

Examples of RNA in a Sentence

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Wang failed her first attempt to defend her dissertation and became envious of her colleague's success in discovering how to deliver RNA to human cells using bacteria, Gomelsky told The Associated Press. — Arkansas Online, 15 Oct. 2026 To profile their activity in patients with SCLC, the researchers analyzed tumor samples and non-affected biopsies from a dozen patients using single-cell RNA sequencing and immunophenotyping. — New Atlas, 15 Oct. 2026 Julie Theriot, a biophysicist at the University of Washington, cautioned that single-cell RNA sequencing is not the only or even the best way to characterize cell states. — Quanta Magazine, 9 Oct. 2026 Nearly every protein on Earth is built from one mirror-image form of each amino acid, and DNA and RNA from one form of sugars. — Mallory Green, The Conversation, 8 Oct. 2026 See All Example Sentences for RNA

Word History

Etymology

ribonucleic acid

First Known Use

1942, in the meaning defined above

Time Traveler
The first known use of RNA was in 1942

Phrases Containing RNA

Browse Nearby Words

RN
RNA
RNAi
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Cite this Entry

“RNA.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/RNA. Accessed 20 Oct. 2026.

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Kids Definition

RNA

noun
ˌär-ˌen-ˈā How to pronounce RNA (audio)
: any of various nucleic acids that are typically found in the cytoplasm of cells, are usually composed of a single chain of nucleotides, differ from DNA in containing ribose as the five-carbon sugar instead of deoxyribose, and that function mostly in protein synthesis

called also ribonucleic acid

compare messenger rna, ribosomal rna, transfer rna

Medical Definition

RNA

noun
ˌär-ˌen-ˈā How to pronounce RNA (audio)
: any of various nucleic acids that contain ribose and uracil as structural components and are associated with the control of cellular chemical activities

called also ribonucleic acid

see messenger rna, ribosomal rna, transfer rna

More from Merriam-Webster on RNA

Britannica.com: Encyclopedia article about RNA

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