Answer:
doyen,
old hand,
old-timer,
stager,
vet,
warhorse.
Explanation:
Title 38 of the Code of Federal Regulations defines a veteran as “a person who served in the active military, naval, or air service and who was discharged or released under conditions other than dishonorable.” This definition explains that any individual that completed a service for any branch of armed forces classifies as a veteran as long as they were not dishonorably discharged. However, with regard to applicable benefits, other considerations are important and will be covered in later sections.