1 : located, seen, or used on the outside or surface of something
the external features of the building
the external signs of the disease
This medication is intended only for external use. (=for use on the skin)
— opposite INTERNAL
2 : coming from outside
external pressures
external stimuli
— opposite INTERNAL
3 : existing or occurring outside your mind
external reality
— opposite INTERNAL
4 : concerning relationships with foreign countries
external (=foreign, international) affairs
— opposite INTERNAL
— externally adverb