Literally, to move something from a distance (tele meaning from a distance, kenesis meaning motion).
I have the power of telekenesis, so i threw a car at my sister.
I pushed a ball with a stick which, by defintion, is telekenesis.
The ability to move, pick-up, or otherwise manipulate an object with ones mind.
Telekenesis is featured well in the game "Psi-Ops".