As used in this compact, unless the context clearly requires otherwise:
(1) “State” means a state of the United States; the United States of America; a territory or possession of the United States; the District of Columbia; the Commonwealth of Puerto Rico.
(2) “Sending state” means a state party to this compact in which conviction or court commitment was had.
(3) “Receiving state” means a state party to this compact to which an inmate is sent for confinement other than a state in which conviction or court commitment was had.
(4) “Inmate” means a male or female offender who is committed, under sentence to, or confined in a penal or correctional institution.
(5) “Institution” means any penal or correctional facility, including but not limited to a facility for the mentally ill or mentally defective, in which inmates as defined in (d) above may lawfully be confined.