onside

Short definition from Wiktionary

Adjective

1. 1
   Not in an offside position; In the part of the playing area where one can legally play the ball, puck, etc.
2. 2
   Within bounds.
3. 3
   On the side of a vehicle from which the driver, paddler, etc. propels it.
4. 4
   Favourably located, from the point of view of the player taking a finesse.
5. 5
   In agreement or support; on board.

Noun

1. 1
   The portion of the playing area where one can legally play the ball, puck, etc.
2. 2
   The side of a vehicle on which the driver primarily propels it.