The point in the interior of any figure of any number of dimensions that has as its coordinates the arithmetic mean of the coordinates of all points on the perimeter of the figure (or of all points in the interior for a center of volume).
The subgroup (respectively, subring), denoted Z(G), of those elements of a given group (respectively, ring) G that commute with every element of G.
A place where the greater part of some function or activity occurs.
A topic that is particularly important in a given context.
A player in the middle of the playing area
A player who can go all over the court, except the shooting circles.