The Collaborative International Dictionary of English v.0.48:

Insurance \In*sur"ance\, n. [From Insure.]
   [1913 Webster]
   1. The act of insuring, or assuring, against loss or damage
      by a contingent event; a contract whereby, for a
      stipulated consideration, called premium, one party
      undertakes to indemnify or guarantee another against loss
      by certain specified risks. Cf. Assurance, n., 6.
      [1913 Webster]

   Note: The person who undertakes to pay in case of loss is
         termed the insurer; the danger against which he
         undertakes, the risk; the person protected, the
         insured; the sum which he pays for the protection, the
         premium; and the contract itself, when reduced to form,
         the policy. --Johnson's Cyc.
         [1913 Webster]

   2. The premium paid for insuring property or life.
      [1913 Webster]

   3. The sum for which life or property is insured.
      [1913 Webster]

   4. A guaranty, security, or pledge; assurance. [Obs.]
      [1913 Webster]

            The most acceptable insurance of the divine
            protection.                           --Mickle.
      [1913 Webster]

   5. Hence: Any means of assuring against loss; a precaution;
      as, we always use our seat belts as insurance against
      injury.
      [PJC]

   Accident insurance, insurance against pecuniary loss by
      reason of accident to the person.

   Endowment insurance or Endowment assurance, a combination
      of life insurance and investment such that if the person
      upon whose life a risk is taken dies before a certain
      specified time the insurance becomes due at once, and if
      he survives, it becomes due at the time specified. Also
      called whole life insurance.

   Fire insurance. See under Fire.

   Insurance broker, a broker or agent who effects insurance.


   Insurance company, a company or corporation whose business
      it is to insure against loss, damage, or death.

   Insurance policy, a certificate of insurance; the document
      containing the contract made by an insurance company with
      a person whose property or life is insured.

   Life insurance. See under Life.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Broker \Bro"ker\ (br[=o]"k[~e]r), n. [OE. brocour, from a word
   akin to broken, bruken, to use, enjoy, possess, digest, fr.
   AS. br[=u]can to use, enjoy; cf. Fries. broker, F.
   brocanteur. See Brook, v. t.]
   1. One who transacts business for another; an agent.
      [1913 Webster]

   2. (Law) An agent employed to effect bargains and contracts,
      as a middleman or negotiator, between other persons, for a
      compensation commonly called brokerage. He takes no
      possession, as broker, of the subject matter of the
      negotiation. He generally contracts in the names of those
      who employ him, and not in his own. --Story.
      [1913 Webster]

   3. A dealer in money, notes, bills of exchange, etc.
      [1913 Webster]

   4. A dealer in secondhand goods. [Eng.]
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   5. A pimp or procurer. [Obs.] --Shak.
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   Bill broker, one who buys and sells notes and bills of
      exchange.

   Curbstone broker or Street broker, an operator in stocks
      (not a member of the Stock Exchange) who executes orders
      by running from office to office, or by transactions on
      the street. [U.S.]

   Exchange broker, one who buys and sells uncurrent money,
      and deals in exchanges relating to money.

   Insurance broker, one who is agent in procuring insurance
      on vessels, or against fire.

   Pawn broker. See Pawnbroker.

   Real estate broker, one who buys and sells lands, and
      negotiates loans, etc., upon mortgage.

   Ship broker, one who acts as agent in buying and selling
      ships, procuring freight, etc.

   Stock broker. See Stockbroker.
      [1913 Webster]

WordNet (r) 3.0 (2006):

insurance broker
    n 1: an agent who sells insurance [syn: insurance broker,
         insurance agent, general agent, underwriter]