\begin{definition}[Definition:Pole of Great Circle]
This is a special case of the pole of a circle.
Let $S$ be a sphere whose center is $O$.
Let $C$ be a great circle of $S$.
Let $AB$ be the diameter of $S$ situated perpendicular to the plane of $C$.
:700px
The points $A$ and $B$, where the diameter intersects $S$, are the '''poles''' of the great circle $C$.
\end{definition}