capsid

noun

cap·​sid ˈkap-səd 

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

Examples of capsid in a Sentence

Recent Examples on the Web

Once inside the host cell, the capsid is shed, and the virus begins copying itself. — New Atlas, 26 July 2025

Our language model also identified a novel viral capsid protein that is widespread in the global oceans. — Libusha Kelly, The Conversation, 15 May 2024

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

Word History

Etymology

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

First Known Use

1959, in the meaning defined above

Medical Definition

capsid

noun

cap·​sid ˈkap-səd 

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

capsidal

-səd-ᵊl 

adjective