A point which does not lie on at least one ordinary line.
Special Point
See also
Ordinary PointExplore with Wolfram|Alpha
References
Guy, R. K. "Unsolved Problems Come of Age." Amer. Math. Monthly 96, 903-909, 1989.Referenced on Wolfram|Alpha
Special PointCite this as:
Weisstein, Eric W. "Special Point." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/SpecialPoint.html