The Collaborative International Dictionary of English v.0.48:

Collector \Col*lect"or\, n. [LL. collector one who collects: cf.
   F. collecteur.]
   1. One who collects things which are separate; esp., one who
      makes a business or practice of collecting works of art,
      objects in natural history, etc.; as, a collector of
      coins.
      [1913 Webster]

            I digress into Soho to explore a bookstall. Methinks
            I have been thirty years a collector. --Lamb.
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   2. A compiler of books; one who collects scattered passages
      and puts them together in one book.
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            Volumes without the collector's own reflections.
                                                  --Addison.
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   3. (Com.) An officer appointed and commissioned to collect
      and receive customs, duties, taxes, or toll.
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            A great part of this is now embezzled . . . by
            collectors, and other officers.       --Sir W.
                                                  Temple.
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   4. One authorized to collect debts.
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   5. A bachelor of arts in Oxford, formerly appointed to
      superintend some scholastic proceedings in Lent. --Todd.
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WordNet (r) 3.0 (2006):

collector
    n 1: a person who collects things [syn: collector,
         aggregator]
    2: a person who is employed to collect payments (as for rent or
       taxes) [syn: collector, gatherer, accumulator]
    3: a crater that has collected cosmic material hitting the earth
    4: the electrode in a transistor through which a primary flow of
       carriers leaves the region between the electrodes