: the protein shell of a virus particle surrounding its nucleic acid

Examples of capsid 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.
Once inside the host cell, the capsid is shed, and the virus begins copying itself. — New Atlas, 26 July 2025 But a series of stunning discoveries found that the capsid cone not only survives infection but plays a far more complex role in the production of new viruses. — Jon Cohen, New Yorker, 24 June 2025 Many other viruses have their own capsid proteins, which form a shell around their genetic material, so this drug’s triumph raises the exciting prospect that similar capsid inhibitors could fight other viral diseases. — science.org, 12 Dec. 2024 Our language model also identified a novel viral capsid protein that is widespread in the global oceans. — Libusha Kelly, The Conversation, 15 May 2024

Word History

Etymology

French capside, from Latin capsa case + French -ide -id entry 2

First Known Use

1959, in the meaning defined above

Time Traveler
The first known use of capsid was in 1959

Browse Nearby Words

Cite this Entry

“Capsid.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/capsid. Accessed 26 Sep. 2026.

Medical Definition

: the protein shell of a virus particle that surrounds its nucleic acid
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