Definitions for orthocenterˈɔr θəˌsɛn tər
Random House Webster's College Dictionary
or•tho•cen•terˈɔr θəˌsɛn tər(n.)
the point of intersection of the three altitudes of a triangle.
Origin of orthocenter:
: the intersection of the three lines that can be drawn flowing from the three corners of a triangle to a point along the opposite side where each line intersect that side at a 90 degree angle; in an acute triangle, it is inside the triangle; in an obtuse triangle, it is outside the triangle.