Midfield is the part of a sports pitch that lies approximately in the center. It is a term most commonly associated with football

Football (soccer)

Association football, more commonly known as football or soccer, is a sport played between two teams of eleven players with a spherical ball...

 to refer to the area in and around the center circle, as well as the players who occupy that region, but it can be used in field hockey

Field hockey

Field Hockey, or Hockey, is a team sport in which a team of players attempts to score goals by hitting, pushing or flicking a ball into an opposing team's goal using sticks...

 to describe the same area, or in rugby

Rugby football

Rugby football is a style of football named after Rugby School in the United Kingdom. It is seen most prominently in two current sports, rugby league and rugby union.-History:...

 to refer to the area occupied by the players in the center positions. The term "midfield" is also used in baseball

Baseball

Baseball is a bat-and-ball sport played between two teams of nine players each. The aim is to score runs by hitting a thrown ball with a bat and touching a series of four bases arranged at the corners of a ninety-foot diamond...

to describe the area between the infield and the outfield.