Collocations for veteran - noun

combat (esp. AmE), war
army, military, navy
decorated (esp. AmE)
battle-hardened
ageing/aging, old
retired
disabled, wounded
returning (esp. AmE)
Vietnam, World War Two, etc.

honour/honor
Were veterans honoured and adequately rewarded for their sacrifice?

fight, serve
veterans who served in Vietnam

return
Veterans returned to heroes' welcomes.

veteran of
a veteran of World War Two

battle-scarred, grizzled, long-time (esp. AmE), seasoned
He is now a grizzled veteran of TV shows.
He's a seasoned veteran of the political establishment.

wily
eight-year, seven-year, etc.
an eight-year veteran of the New York Yankees

industry

campaigner, leader, politician
broadcaster, reporter
actor, director
defender, pitcher, player, quarterback, etc. (sports)

veteran of
a veteran of numerous political campaigns