Definition of capillary in English:



  • 1Anatomy
    Any of the fine branching blood vessels that form a network between the arterioles and venules.

    • ‘Blood obtained from a skin puncture is a mixture of arterioles, venules and capillaries and contains interstitial and intracellular fluids.’
    • ‘Between the arteries and the veins are networks of tiny blood vessels called capillaries.’
    • ‘Arterial insufficiency can occur at any level, from large arteries to arterioles and capillaries.’
    • ‘This encroachment on brain tissue by enlarged ventricles impinges on the caliber of arterioles and capillaries, often resulting in ischemia.’
    • ‘Immature vessels coalesce to form larger vessels and organize into capillaries, arterioles, and venules.’
  • 2A tube which has an internal diameter of hair-like thinness.

    • ‘Different diameter capillary tubes are used for thinner or thicker oils.’
    • ‘The packed cell volume is determined by centrifuging the specimen in capillary tubes and measuring the height of the red cell column.’
    • ‘Scientists have long used ultra-fine glass tubes known as capillaries to analyze the chemical makeup of substances.’
    • ‘It was confirmed that repeated heating does not result in any changes in the inner diameter of the capillary.’
    • ‘When a capillary, a narrow tube, touches the surface of a liquid, fluid rises into the tube.’


  • [attributive] Relating to capillaries or capillarity.

    ‘capillary blood’
    • ‘While patients with insulin-requiring diabetes are in active labor, capillary blood glucose levels should be monitored hourly.’
    • ‘It enabled bedside monitoring in critically ill patients by measuring heart output and capillary pressure in the lungs.’
    • ‘Alveolar wall thickening with eosinophilic materials and capillary congestion with red blood cells were evident in the mice with emphysema at 72 hours.’
    • ‘One of the most colorful controversies in the first decade of the 20th century concerned how oxygen moved across the pulmonary capillary wall into the blood.’
    • ‘Dyck and Craig employed capillary electrophoresis as the medium for single-molecule enzyme isolation.’


Mid 17th century: from Latin capillaris, from capillus hair, influenced by Old French capillaire.