noun
1. : the position on the armature of a direct-current machine where the magnetic flux from the field poles is zero, being midway between the poles at no load
2.
a. : a space between the two lines of scrimmage in American football equivalent to the length of the ball that may not be encroached upon by either team until the ball is put in play
b. : the portion of an ice hockey rink between the attacking and defensive zones — see ice hockey illustration