Warrant
noun
Authorization or certification; a sanction, as given by a superior.
Something that provides assurance or confirmation; a guarantee or proof.
“a warrant of authenticity; a warrant for success”
An order that serves as authorization; especially a voucher authorizing payment or receipt of money.
Synonyms: warren earth
verb
To protect, keep safe (from danger).
To give (someone) an assurance or guarantee (of something); also, with a double object: to guarantee (someone something).
To guarantee (something) to be (of a specified quality, value, etc.).