rubicon

noun2

1. •
   A limit that when surpassed cannot be returned from, or an action that when taken cannot be reversed.
2. •
   Especially in bezique and piquet: a score which, if not achieved by a losing player, increases the player's penalty.

   • The game is called a double, and you score 200 instead of 100 when your adversary does not get 100, which, in technical language, is called crossing the Rubicon. — 1873

verb1

1. •
   Especially in bezique and piquet: to defeat a player who has not achieved the rubicon.

   • Fleming initiated me into the mysteries of Bézique, and at once set about rubiconing me, [...] — 1934

noun1

1. •
   (historical) A small river in northeastern Italy which flowed into the Adriatic Sea marking the boundary between the Roman province of Gaul and the Roman heartland. Its crossing by Julius Caesar in 49 B.C.E. began a civil war.