(usually in the plural) The noun "external" represents the exterior or outward features or appearances, including inessential or superficial features and outward appearance.

(programming, in the C language) A variable that is defined in the source code but whose value comes from some external source.

An adjective "external" refers to something situated outside of something, whether it be on the exterior, near the surface of the body, or relating to a medicine or substance used on the outside of the body.

Capable of being perceived outwardly, having the outward appearance of something, and not intrinsic or essential.

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.