Keeper of a magnet

Keeper \Keep"er\, n.
   1. One who, or that which, keeps; one who, or that which,
      holds or has possession of anything.
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   2. One who retains in custody; one who has the care of a
      prison and the charge of prisoners.
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   3. One who has the care, custody, or superintendence of
      anything; as, the keeper of a park, a pound, of sheep, of
      a gate, etc.; the keeper of attached property; hence, one
      who saves from harm; a defender; a preserver.
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            The Lord is thy keeper.               --Ps. cxxi. 6.
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   4. One who remains or keeps in a place or position.
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            Discreet; chaste; keepers at home.    --Titus ii. 5.
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   5. A ring, strap, clamp, or any device for holding an object
      in place; as:
      (a) The box on a door jamb into which the bolt of a lock
          protrudes, when shot.
      (b) A ring serving to keep another ring on the finger.
      (c) A loop near the buckle of a strap to receive the end
          of the strap.
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   6. A fruit that keeps well; as, the Roxbury Russet is a good
      keeper. Hence: Anything perishable that remains in good
      condition longer than usual. -- Downing.
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   7. An iron bar that is placed on the poles of a horseshoe
      magnet, and held in place there by the magnetic force, to
      preserve the strength of the magnet when not in use.
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   {Keeper of the forest} (O. Eng. Law), an officer who had the
      principal government of all things relating to the forest.
      

   {Keeper of the great seal}, a high officer of state, who has
      custody of the great seal. The office is now united with
      that of lord chancellor. [Eng.]

   {Keeper of the King's conscience}, the lord chancellor; -- a
      name given when the chancellor was an ecclesiastic. [Eng.]
      

   {Keeper of the privy seal} (styled also {lord privy seal}), a
      high officer of state, through whose hands pass all
      charters, pardons, etc., before they come to the great
      seal. He is a privy councillor, and was formerly called
      {clerk of the privy seal}. [Eng.]

   {Keeper of a magnet}, a piece of iron which connects the two
      poles, for the purpose of keeping the magnetic power
      undiminished; an armature; called also {keeper}.
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