extreme point

Short definition from Wiktionary

Noun

1. 1
   A point in a convex set which does not lie in any open line segment joining two points in the set.
2. 2
   The maximum or minimum of a function.
3. 3
   A leaf vertex of a tree data structure.
4. 4
   A point that is physically located farthest in the direction of the edge of something.
5. 5
   A standpoint that goes farthest in some dimension or on some criterion.