adjective
Outside of something; on the exterior.
Capable of being perceived outwardly.
Provided by something or someone outside of the entity (object, group, company etc.) considered.
Relating to or connected with foreign nations or institutions.
Having existence independent of the mind.
(education) For or concerning students registered with and taking the examinations of a university but not resident there.
(computing, of a hardware) Not contained in the main computer.
(computing, of storage) Using a disk or tape drive rather than the main memory.
noun
(usually in the plural) The exterior; outward features or appearances.
(programming, in the C language) A variable that is defined in the source code but whose value comes from some external source.