The term ARNESS refers to actor James Arness, best known for his role as Marshal Matt DILLON in the long-running television series 'Gunsmoke'. He was also the older brother of actor Peter Graves. Arness starred in 'Gunsmoke' from 1955 to 1975, making him one of the longest-running actors in a single role in television history. He also appeared in several films, including 'Big Jim McLain' and 'The Sea Chase'.