Definition of "Lag" :
noun: the act of slowing down or falling behind
noun: one of several thin slats of wood forming the sides of a barrel or bucket
noun: the time between one event, process, or period and another
verb: cover with lagging to prevent heat loss
verb: throw or pitch at a mark, as with coins
verb: hang (back) or fall (behind) in movement, progress, development, etc.
verb: lock up or confine, in or as in a jail