Dictionary.net

A tax imposed by a state to compensate for the sales tax lost when an item is purchased outside of the state, but is used within the state. For example, you buy your car in a state that has no sales tax, but you live across the border in a state that does have a sales tax. When you bring your car home and register it in your state, the state taxing authority will bill you for the sales tax it would have collected had you bought the car within the state.

Charge on items used in a jurisdiction but purchased somewhere else.