Definition of dead weights:
(n) :
(figuratively) That which is useless or excess; that which slows something down.
(n) :
Unremitting heavy weight that does not move.
(n) :
(nautical) The largest weight of cargo a ship is able to carry; i.e., the weight of a ship when fully loaded minus its weight when empty.
(n) :
(rail transport) The total (unpowered) weight of a train to be propelled (or hauled) by the locomotive; another locomotive being hauled dead as part of the train is a dead weight.
(n) :
(construction) A dead load.
(adv) :
(of a shot in snooker or other cue sports) With just enough weight for a ball to drop into a pocket, or come to rest in a precisely determined position.