In tennis, the term "deuce" refers to a situation where the score is tied at 40-40. To win the game from this point, a player must secure two consecutive points: the first point after deuce is called "advantage", and winning the subsequent point results in winning the game. If the player with the advantage fails to win the next point, the score resets back to deuce. This term adds strategic complexity to the game and can create intense moments during matches, heightening the overall drama of competitive play.