Two-transitive group action
= Two-transitive group action
= Two-transitive action
{synonym}
= Two-transitive
{synonym}
= Doubly transitive group action
{synonym}
= Two-transitivity
{synonym}
A group action on a set is two-transitive when it acts transitively on ordered pairs of distinct points. Equivalently, a point stabilizer acts transitively on the remaining points.
This is the $k=2$ case of a <multiply transitive group action>.