adj. & n.
adj. 1 a of or situated on the outside or visible part (opp. INTERNAL). b coming or derived from the outside or an outside source. 2 relating to a country's foreign affairs. 3 outside the conscious subject (the external world). 4 (of medicine etc.) for use on the outside of the body. 5 for or concerning students taking the examinations of a university without attending it.
n. (in pl.) 1 the outward features or aspect. 2 external circumstances. 3 inessentials. external evidence evidence derived from a source independent of the thing discussed. externality n. (pl. -ies). externally adv.
[ med.L f. L externus f. exterus outside ]