Dictionary.com
Thesaurus.com

capsid

1 American  
[kap-sid] / ˈkæp sɪd /

noun

Microbiology.

  1. the coiled or polyhedral structure, composed of proteins, that encloses the nucleic acid of a virus.

capsid 2 American  
[kap-sid] / ˈkæp sɪd /

noun

  1. plant bug.

capsid 1 British  
/ ˈkæpsɪd /

noun

  1. the outer protein coat of a mature virus

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
capsid 2 British  
/ ˈkæpsɪd /

noun

  1. any heteropterous bug of the family Miridae (formerly Capsidae ), most of which feed on plant tissues, causing damage to crops

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
capsid Scientific  
/ kăp′sĭd /

  1. The protein shell that surrounds a virus particle (known as a virion).

  2. See more at virus

Etymology

Origin of capsid1

1960–65; < French capside, equivalent to Latin caps ( a ) case 2 + -ide -id 1

Origin of capsid2

< New Latin Capsidae, equivalent to Caps ( us ) a genus (said to have been formed on Greek kápsis a gulping down; káp ( tein ) to gulp down + -sis -sis ) + -idae -id 2

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Its capsid surface contains multiple spike structures topped with unique caps, some with filament-like extensions not seen in medusaviruses.

From Science Daily • Feb. 19, 2026

Medusavirus is known for its icosahedral shape and numerous short spikes covering its capsid surface.

From Science Daily • Feb. 19, 2026

Our language model also identified a novel viral capsid protein that is widespread in the global oceans.

From Salon • May 17, 2024

The researchers showed that the compound K11777 prevents host cells from helping the virus out of its shell by cleaving the viral capsid.

From Science Daily • May 15, 2024

They also found that the DNA organized itself into domains conforming to the topology of the capsid.

From Science Daily • Mar. 7, 2024

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.