1. An act, instrument, or obligation, by which one person authorizes another to do something which he has not otherwise a right to do; an act or instrument investing one with a right or authority, and thus securing him from loss or damage; authority; commission; sanction.
2. A legal instrument ordering a judicial act, such as an arrest, search, etc., to be executed by an officer of the court.
3. A writing that authorizes a person to receive money or other things; a license.
4. The certificate of appointment given to a noncommissioned officer or the Army or Navy.
5. A voucher; that which attests or proves; an attestation.
6. That which secures; security; guarantee, pledge; assurance given.