Lighter \Light"er\, n. [D. ligter, fr. ligt light. See {Light} not heavy.] (Naut.) A large boat or barge, mainly used in unloading or loading vessels which can not reach the wharves at the place of shipment or delivery. [1913 Webster] {Lighter screw} (Mach.), a screw for adjusting the distance between the stones in a grinding mill by raising or lowering the bridgetree. [1913 Webster]