Definition of rolloff:
(n) :
A rolloff dumpster.
(adj) :
(of a dumpster) Able to be rolled off (and later, rolled back onto) the bed of a flatbed truck (flatbed lorry) in a motorized way, using a winch and cable.
(n) :
(aviation) A sudden large uncommanded roll to the left or right experienced by an aircraft entering a stall, resulting from one wing stalling slightly before the other and exacerbated by the reduction in aileron control authority at high angles of attack.