hasp / hasp/ • n. a slotted hinged metal plate that forms part of a fastening for a door or lid and is fitted over a metal loop and secured by a pin or padlock. ∎ a similar metal plate on a trunk or suitcase with a projecting piece that is secured by the lock. • v. [tr.] archaic lock (a door, window, or lid) by securing the hasp over the loop of the fastening.