capillary

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Relating to or resembling a hair; fine and slender.
• adjective Having a very small internal diameter.
• adjective Anatomy Of or relating to the capillaries.
• adjective Physics Of or relating to capillarity.
• noun Anatomy One of the minute blood vessels that connect arterioles and venules. These blood vessels form an intricate network throughout the body for the interchange of various substances, such as oxygen and carbon dioxide, between blood and tissue cells.
• noun A tube with a very small internal diameter.

from The Century Dictionary.

• Pertaining to or resembling hair: as, a capillary lotion; capillary fibers or threads.
• Specifically, in botany, resembling hair in the manner of growth: applied in this sense by Ray, Boerhaave, and other early botanists to ferns.
• Resembling a single hair; specifically, in anatomy, having (as a tube) so small a bore that water cannot be poured into it, and will not run through it.
• Pertaining to a capillary or to capillaries: as, capillary circulation.
• Pertaining to the phenomena of the rise of fluids in tubes and chinks, and, more generally, to the collecting of liquids in drops, their spreading over surfaces (as oil on water), and various other phenomena explicable proximately by surface-tension and ultimately by cohesion and adhesion, considered as forces acting at finite but insensible distances.
• In surgery, linear: descriptive of a fracture of the skull without separation of the parts of the injured bones.
• noun pl. capillaries (-riz).
• noun A tube with a small bore. Specifically
• noun In anatomy: One of the minute blood-vessels which form a network between the terminations of the arteries and the beginnings of the veins.
• noun One of the minute lymphatic ducts.
• noun One of the intercellular passages in the liver which unite to form the bile-ducts.
• noun In botany, a fern: especially applied to such ferns as grow like tufts of hair on walls. Sir T. Browne. See I., 2.

from the GNU version of the Collaborative International Dictionary of English.

• adjective Resembling a hair; fine; minute; very slender; having minute tubes or interspaces; having very small bore.
• adjective Pertaining to capillary tubes or vessels.
• adjective the apparent attraction or repulsion between a solid and liquid caused by capillarity. See Capillarity, and Attraction.
• adjective See the Note under Capillarity.
• noun A tube or vessel, extremely fine or minute.
• noun (Anat.) A minute, thin-walled vessel; particularly one of the smallest blood vessels connecting arteries and veins, but used also for the smallest lymphatic and biliary vessels.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective of or pertaining to hair
• adjective pertaining to a narrow tube
• noun A narrow tube
• noun anatomy Any of the small blood vessels that connect arteries to veins

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a tube of small internal diameter; holds liquid by capillary action
• adjective long and slender with a very small internal diameter
• noun any of the minute blood vessels connecting arterioles with venules
• adjective of or relating to hair