Definitions for "Unforced error"
Loss of a point caused by a poorly hit shot that goes into the net or out of the court. Compare forced error.
Where a player is not under any pressure from an opponent yet plays a shot which does not land in the court.
a tennis reference and can result from several outcomes, but it's always a lost point that has little to do with the opponent
A ball that is not kept in play that should have been.
if a player does not return the ball to the court, although they could have done so.