warrant

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An order that serves as authorization, especially.
• noun Law A judicial writ authorizing the search or seizure of property, arrest of a person, or the execution of a legal judgment.
• noun A voucher authorizing payment or receipt of money.
• noun An option to buy stock at a specified price from an issuing company.
• noun Justification for an action or a belief; grounds.
• noun Something that provides assurance or confirmation; a guarantee or proof.
• noun Authorization or certification; sanction, as given by a superior.
• noun A warrant officer.
• noun A certificate of appointment given to a warrant officer.
• transitive verb To provide adequate grounds for; justify or require.
• transitive verb To guarantee (a product).
• transitive verb To guarantee (a purchaser) indemnification against damage or loss.
• transitive verb Law To guarantee clear title to (real property).

from The Century Dictionary.

• noun Protector; protection; defense; safeguard.
• noun Security; guaranty; assurance; voucher; attestation; evidence; pledge; that which attests or proves.
• noun Authority; authorization; sanction; justification.
• noun 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 with authority, and thus securing him from blame, loss, or damage; hence, anything which authorizes or justifies an act; a license.
• noun Specifically— An instrument or negotiable writing authorizing a person to receive money or other things: as, a dividend warrant. See dock- warrant.
• noun In law, an instrument authorizing the officer to whom it is issued to seize or detain a person or property, or carry a judgment into execution. Some instruments used for such a purpose are, however, called writs, executions, etc., rather than warrants.
• noun In the army and navy, a writ or authority inferior to a commission. See warrant-officer.
• noun In coal-mining, underclay.
• To protect; defend; safeguard; secure.
• To guarantee or assure against harm; give assurance or surety to; give authority or power to do or forbear anything by which the person thus authorized or empowered is secured or saved harmless from any loss or damage which may result from such act or forbearance.
• To give guaranty or assurance for, as the truth or the due performance of something; give one's word for or concerning.
• To declare with assurance or without fear of contradiction or failure; assert as undoubted; pledge one's word: used in asseverations and governing a clause.
• To make certain or secure; assure by warrant or guaranty.
• To give a pledge or assurance in regard to; guarantee (something) to be safe, sound, genuine, or as represented: as, to warrant a horse; warranted goods.
• To support by authority or proof; afford ground for; authorize; justify; sanction; support; allow.

from the GNU version of the Collaborative International Dictionary of English.

• transitive verb To make secure; to give assurance against harm; to guarantee safety to; to give authority or power to do, or forbear to do, anything by which the person authorized is secured, or saved harmless, from any loss or damage by his action.
• transitive verb To support by authority or proof; to justify; to maintain; to sanction.
• transitive verb To give a warrant or warranty to; to assure as if by giving a warrant to.
• transitive verb To secure to, as a grantee, an estate granted; to assure.
• transitive verb To secure to, as a purchaser of goods, the title to the same; to indemnify against loss.
• transitive verb To secure to, as a purchaser, the quality or quantity of the goods sold, as represented. See Warranty, n., 2.
• transitive verb To assure, as a thing sold, to the purchaser; that is, to engage that the thing is what it appears, or is represented, to be, which implies a covenant to make good any defect or loss incurred by it.
• noun That which warrants or authorizes; a commission giving authority, or justifying the doing of anything; 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; commission; authority.
• noun A writing which authorizes a person to receive money or other thing.
• noun (Law) A precept issued by a magistrate authorizing an officer to make an arrest, a seizure, or a search, or do other acts incident to the administration of justice.
• noun (Mil. & Nav.) An official certificate of appointment issued to an officer of lower rank than a commissioned officer. See Warrant officer, below.
• noun That which vouches or insures for anything; guaranty; security.
• noun That which attests or proves; a voucher.
• noun obsolete Right; legality; allowance.
• noun (Law) See in the Vocabulary.
• noun (Com.) a customhouse license or authority.
• noun (Law) See under General.
• noun See under Land.