Lag

Whereas latency is usually measured in milliseconds (ping) and is therefore a quantitative value, "lag" is purely qualitative. When discussing lag it is typically used as in "this is bad lag," "the lag sucks," or "laggy mclaggenstein went and lagged out." ("Lagging out" is a phrase referring to when someone goes link-dead and is disconnected in an online game due to latency or connection issues.)