The Collaborative International Dictionary of English v.0.48:

Mirror \Mir"ror\, n. [OE. mirour, F. miroir, OF. also mireor,
   fr. (assumed) LL. miratorium, fr. mirare to look at, L.
   mirari to wonder. See Marvel, and cf. Miracle,
   Mirador.]
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   1. A looking-glass or a speculum; any glass or polished
      substance that forms images by the reflection of rays of
      light.
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            And in her hand she held a mirror bright,
            Wherein her face she often view[`e]d fair.
                                                  --Spenser.
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   2. That which gives a true representation, or in which a true
      image may be seen; hence, a pattern; an exemplar.
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            She is mirour of all courtesy.        --Chaucer.
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            O goddess, heavenly bright,
            Mirror of grace and majesty divine.   --Spenser.
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   3. (Zool.) See Speculum.
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   Mirror carp (Zool.), a domesticated variety of the carp,
      having only three or fur rows of very large scales side.


   Mirror plate.
      (a) A flat glass mirror without a frame.
      (b) Flat glass used for making mirrors.

   Mirror writing, a manner or form of backward writing,
      making manuscript resembling in slant and order of letters
      the reflection of ordinary writing in a mirror. The
      substitution of this manner of writing for the common
      manner is a symptom of some kinds of nervous disease.
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WordNet (r) 3.0 (2006):

mirror carp
    n 1: domestic carp with some large shining scales