Per Article 1,
|"Veteran” means a player who has signed at least one Player Contract with an NFL Club.
The practical significance of this definition is pretty limited; for example, it determines whether a player's contract counts toward the Rookie Compensation Pool. Under this definition, Jake Ballard and Victor Cruz are both "veterans", although Ballard is also a first-year player and Cruz has never dressed for a regular season game.
The more common, colloquial definition of a veteran is a player with at least one year of credited NFL experience. Nfl.com shows an "Experience" number greater than 1 for such players. (Rookies have a 0; first-year players like Ballard have a 1.) Even here, things get a bit murky. By this test, Ballard is still a first-year player (though not a rookie) because he was not on full-pay status for at least six games in 2010 and therefore did not earn a credited year. Cruz is considered a second-year player because he earned a credited season on IR. Confusingly, Ballard has less credited experience than Cruz, although Ballard actually played last year and Cruz didn't.
Another important category, formerly known as "vested veterans" comprises players with at least four credited seasons. They are eligible for unrestricted free agency, full termination pay and other privileges. The term "vested vet" has fallen out of use, probably because the vesting requirements for the retirement plan have become more complex.
With regard to Domenik Hixon, it makes absolutely no difference which definition you use. He has five credited seasons, including his IR year in 2010. He's a veteran no matter how you slice it.