Cap"il*la*ry (kăp"&ibreve;l*l&asl;*r&ybreve; or k&adot;*p&ibreve;l"l&adot;*r&ybreve;; 277), a. [L. capillaris, fr. capillus hair. Cf. Capillaire.] 1. Resembling a hair; fine; minute; very slender; having minute tubes or interspaces; having very small bore; as, the capillary vessels of animals and plants.

2. Pertaining to capillary tubes or vessels; as, capillary action.

Cap"il*la*ry, n.; pl. Capillaries (&?;). 1. A tube or vessel, extremely fine or minute.

2. (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.

• (anatomy) Any of the small blood vessels that connect arterioles to venules. Their walls are composed of a single layer of cells which allows molecules such as oxygen, water and lipids to pass through them by diffusion and enter the tissues. Waste products such as carbon dioxide and urea can diffuse back into the blood to be carried away for removal from the body.