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

"Lag pipes."

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