Definition of efferent in US English:



  • Conducted or conducting outward or away from something (for nerves, the central nervous system; for blood vessels, the organ supplied)

    ‘efferent neurons carry impulses outwards to the effector organs’
    The opposite of afferent
    • ‘Anterior or efferent nerve roots convey efferent impulses from the spinal cord to the body, and posterior nerve roots convey afferent or sensory input from skin regions to the spinal cord.’
    • ‘During lung transplantation, both the afferent and efferent nerves that supply the lung are severed.’
    • ‘The opposite occurs when sympathetic impulses constrict efferent arterioles.’
    • ‘The axons of both classes of interneuron enter the brain via the ocellar nerve, which also carries the axons of efferent neurons.’
    • ‘Sacral nerves contain a mixture of autonomic and somatic fibers that send information in both afferent and efferent directions.’


Mid 19th century: from Latin efferent- ‘carrying out’, from the verb efferre, from ex- ‘out’ + ferre ‘carry’.