Capillary

Part of speech: noun (n.)

1. A tube or vessel, extremely fine or minute.

2. 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.

Part of speech: adjective (a.)

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. Capillary attraction, Capillary repulsion, the apparent attraction or repulsion between a soild and liquid caused bycapillarity. See Capillarity, and Attraction. -- Capillarity tubes. See the Note under Capillarity.