2.verbTo get rid of things, work, or problems by passing them on to someone or something else.
"He offloaded the defective car onto an unsuspecting buyer."
3.verbTo pass the ball.
4.verb(travel) to deny a person on a standby list due to lack of space.
5.verb(travel) to change a passengers' ticket status from "checked in" to "open", allowing further changes. (This applies regardless of whether the passenger has boarded the aircraft or not).