Definition of "capillary"

Of or pertaining to hair.  examples

Of or pertaining to a narrow tube.  examples

Of, relating to, or caused by surface tension.  examples

A narrow tube.  examples

(anatomy) Any of the small blood vessels (from 5 to 10 micrometres/micrometers (μm) in diameter) that connect arteries to veins (They are the smallest blood vessels in the body: they convey blood between the arterioles and venules).  examples