• synonyms


See more synonyms for capillary on Thesaurus.com
  1. pertaining to or occurring in or as if in a tube of fine bore.
  2. resembling a strand of hair; hairlike.
  3. Physics.
    1. pertaining to capillarity.
    2. of or relating to the apparent attraction or repulsion between a liquid and a solid, observed in capillarity.
  4. Anatomy. pertaining to a capillary or capillaries.
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noun, plural cap·il·lar·ies.
  1. Anatomy. one of the minute blood vessels between the terminations of the arteries and the beginnings of the veins.
  2. Also called capillary tube. a tube with a small bore.
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Origin of capillary

1570–80; capill(ar) (obsolete, < Latin capillāris pertaining to hair, equivalent to capill(us) hair + -āris -ar1) + -ary
Related formsin·ter·cap·il·lar·y, adjectivenon·cap·il·lar·y, adjective, noun, plural non·cap·il·lar·ies.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for capillaries

hair, nerve, seam, lode, stripe, artery, vein, capillary, streak, thread, duct, current, course, stratum, venation, follicle, arteriole, metarteriole, venule

Examples from the Web for capillaries

Historical Examples of capillaries

  • He knew nothing of the vessels which we now speak of as capillaries.

    Fathers of Biology

    Charles McRae

  • Well, Malpighi tried to discover the capillaries by this method, and failed.

  • Hence it is argued that their capillaries show the least permeability.

  • This vein runs to the liver, where it breaks up into capillaries.

  • The whole stream, on the other hand, passes through the capillaries of the lungs.


    Ernest G. Martin

British Dictionary definitions for capillaries


  1. resembling a hair; slender
  2. (of tubes) having a fine bore
  3. anatomy of or relating to any of the delicate thin-walled blood vessels that form an interconnecting network between the arterioles and the venules
  4. physics of or relating to capillarity
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noun plural -laries
  1. anatomy any of the capillary blood vessels
  2. a fine hole or narrow passage in any substance
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Word Origin for capillary

C17: from Latin capillāris, from capillus hair
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

Word Origin and History for capillaries



1650s, "of or pertaining to the hair," from Latin capillaris "of hair," from capillus "hair" (of the head); perhaps related to caput "head" (but de Vaan finds this "difficult on the formal side" and "far from compelling, since capillus is a diminutive, and would mean 'little head', which hardly amounts to 'hair'"). Borrowed earlier as capillar (14c.). Meaning "taking place in capillary vessels" is from 1809. Capillary attraction attested from 1813. As a noun, "capillary blood vessel," from 1660s.

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Online Etymology Dictionary, © 2010 Douglas Harper

capillaries in Medicine


  1. Of or relating to the capillaries.
  2. Relating to or resembling a hair; fine and slender.
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  1. Blood capillary.
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The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

capillaries in Science


  1. Any of the tiny blood vessels that connect the smallest arteries (arterioles) to the smallest veins (venules). Capillaries form a network throughout the body for the exchange of oxygen, metabolic waste products, and carbon dioxide between blood and tissue cells.
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The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

capillaries in Culture



The tiny blood vessels throughout the body that connect arteries and veins. Capillaries form an intricate network around body tissues in order to distribute oxygen and nutrients to the cells and remove waste substances. (See circulatory system.)

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A thin tube, such as a blood vessel or a straw, through which fluids flow.

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The interaction between the fluid and the vessel walls produces a force that can lift the fluid up into the tube, a phenomenon known as capillary action.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.