Source : Webster's Revised Unabridged Dictionary (1913)

Warrant \War"rant\, n. [OE. warant, OF. warant a warrant, a
   defender, protector, F. garant, originally a p. pr. pf German
   origin, fr. OHG. wer[=e]n to grant, warrant, G. gew["a]hren;
   akin to OFries. wera. Cf. {Guarantee}.]
   1. 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. Specifically:
      (a) A writing which authorizes a person to receive money
          or other thing.
      (b) (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.
      (c) (Mil. & Nav.) An official certificate of appointment
          issued to an officer of lower rank than a commissioned
          officer. See {Warrant officer}, below.

   2. That which vouches or insures for anything; guaranty;
      security.

            I give thee warrant of thy place.     --Shak.

            His worth is warrant for his welcome hither. --Shak.

   3. That which attests or proves; a voucher.

   4. Right; legality; allowance. [Obs.] --Shak.

   {Bench warrant}. (Law) See in the Vocabulary.

   {Dock warrant} (Com.), a customhouse license or authority.

   {General warrant}. (Law) See under {General}.

   {Land warrant}. See under {Land}.

   {Search warrant}. (Law) See under {Search}, n.

   {Warrant of attorney} (Law), written authority given by one
      person to another empowering him to transact business for
      him; specifically, written authority given by a client to
      his attorney to appear for him in court, and to suffer
      judgment to pass against him by confession in favor of
      some specified person. --Bouvier.

   {Warrant officer}, a noncommissioned officer, as a sergeant,
      corporal, bandmaster, etc., in the army, or a
      quartermaster, gunner, boatswain, etc., in the navy.

   {Warrant to sue and defend}.
      (a) (O. Eng. Law) A special warrant from the crown,
          authorizing a party to appoint an attorney to sue or
          defend for him.
      (b) A special authority given by a party to his attorney
          to commence a suit, or to appear and defend a suit in
          his behalf. This warrant is now disused. --Burrill.

Search \Search\, n. [Cf. OF. cerche. See {Search}, v. t.]
   The act of seeking or looking for something; quest; inquiry;
   pursuit for finding something; examination.

         Thus the orb he roamed With narrow search, and with
         inspection deep Considered every creature. --Milton.

         Nor did my search of liberty begin Till my black hairs
         were changed upon my chin.               --Dryden.

   {Right of search} (Mar. Law), the right of the lawfully
      commissioned cruisers of belligerent nations to examine
      and search private merchant vessels on the high seas, for
      the enemy's property or for articles contraband of war.

   {Search warrant} (Law), a warrant legally issued, authorizing
      an examination or search of a house, or other place, for
      goods stolen, secreted, or concealed.

   Syn: Scrutiny; examination; exploration; investigation;
        research; inquiry; quest; pursuit.

Source : WordNet®

search warrant
     n : a warrant authorizing law enforcement officials to search
         for objects or people involved in the commission of a
         crime and to produce them in court; the warrant describes
         the locations where the officials may search