offsider

1. (Australia, New Zealand, informal) A partner, assistant, or deputy.Examples: "Kidman, riding hell for leather and carrying a heavy stockwhip, caught up with him soon after, or rather with his offsider, who was tailing the mob, and demanded an explanation for their trespassing. “Don′t ask me,” said the offsider. “You see the boss.”"; "With the 2005 incarnation of Temptation, Livinia Nixon has completed the trifecta of TV seconds: variety offsider, game show hostess and weather girl."; "Tom also brought an offsider. I will never forget the look on the faces of the airline staff when Big Tony hauled his shooter out and slammed it on the counter. Tom and his sidekick did the same. I couldn′t believe these blokes were armed and how cool everyone was about it."AustraliaNew-Zealandinformal