Definition of "extern" in English

noun

1. A person affiliated with an institution in a lesser capacity, for example, as a non-resident or as a part-time affiliate.

2. Outward form or part; exterior.

adjective

1. (obsolete, rare) External; outward; not inherent

noun

1. (programming) In the C and C++ programming languages, a variable that can be separately declared in many places, all of them referring to the same variable.