Given a point 
,
the point 
which is the antipodal point of 
is said to be the antipode of 
.
The term antipode is also used in plane geometry. Given a central conic (or circle) and a point 
lying on it, draw a line passing through 
and the center 
of the conic. Then the antipode 
of 
is other point lying on the conic through which the line 
passes.
The antipode of a vertex 
in a graph is a vertex 
at greatest possible distance from 
. An antipodal graph is
then defined as a connected graph in which each
vertex has exactly one antipode (Gorovoy and Zmiaikou 2021).
