lockful|ˈlɒkfʊl| [f. lock n.2 + -ful.] As much as will fill a lock. 1811Two Rep. Thames Navig. 25 The Canals, some of which have no water, pay heavily for every lockfull forced up by steam-engines.1837Civil Eng. & Archit.Jrnl. I. 44/2 Making 6740 cubic feet or 46,2433/4 gallons of water to each lockful.