circumcenter

[sur-kuh m-sen-ter]
noun Geometry.
  1. the center of a circumscribed circle; that point where any two perpendicular bisectors of the sides of a polygon inscribed in the circle intersect.

Origin of circumcenter

First recorded in 1885–90; circum- + center
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018