Definition of endgames:
(n) :
(by extension) The final stage of any game.
(n) :
(chess) The final stage of a game of chess, when there are few pieces left.
(n) :
(bridge) The final stage of a game of bridge, when there are few cards left.
(n) :
(figuratively) The final stage of an extended process or course of events, especially with the implication of the imminent realization of a masterful strategy or plan.
(n) :
(video games) The gameplay available in a massively multiplayer online role-playing game for players who have completed all of the preset challenges.
(n) :
(crosswording) The thematic element of an advanced cryptic crossword puzzle, typically solved after completing the grid.