When an online game lags (runs slowly) for a period of time, and automatically boots you from their servers to relieve some of the lag.
Lagging Out is most often found in private server MMORPGs, where a person is usually hosting more players than they can handle on their servers.
Lagging Out tends to leave many players frustrated at the game, and much complaining when they log back on.
"I can't believe I just lagged out! It's the 5th time today!"
"If that noob high alchs again we will all lag out..."
by thecrazycamper July 19, 2009