49 CFR § 376.2 - Definitions.
(b) Equipment. A motor vehicle, straight truck, tractor, semitrailer, full trailer, any combination of these and any other type of equipment used by authorized carriers in the transportation of property for hire.
(c) Interchange. The receipt of equipment by one motor carrier of property from another such carrier, at a point which both carriers are authorized to serve, with which to continue a through movement.
(d) Owner. A person (1) to whom title to equipment has been issued, or (2) who, without title, has the right to exclusive use of equipment, or (3) who has lawful possession of equipment registered and licensed in any State in the name of that person.
(e) Lease. A contract or arrangement in which the owner grants the use of equipment, with or without driver, for a specified period to an authorized carrier for use in the regulated transportation of property, in exchange for compensation.
(j) Private carrier. A person, other than a motor carrier, transporting property by motor vehicle in interstate or foreign commerce when (1) the person is the owner, lessee, or bailee of the property being transported; and (2) the property is being transported for sale, lease, rent, or bailment, or to further a commercial enterprise.
(k) Shipper. A person who sends or receives property which is transported in interstate or foreign commerce.
(l) Escrow fund. Money deposited by the lessor with either a third party or the lessee to guarantee performance, to repay advances, to cover repair expenses, to handle claims, to handle license and State permit costs, and for any other purposes mutually agreed upon by the lessor and lessee.
(m) Detention. The holding by a consignor or consignee of a trailer, with or without power unit and driver, beyond the free time allocated for the shipment, under circumstances not attributable to the performance of the carrier.