The Collaborative International Dictionary of English v.0.48:

Queen \Queen\, n. [OE. quen, quene, queen, quean, AS. cw[=e]n
   wife, queen, woman; akin to OS. qu[=a]n wife, woman, Icel.
   kv[=a]n wife, queen, Goth. q[=e]ns. [root]221. See Quean.]
   1. The wife of a king.
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   2. A woman who is the sovereign of a kingdom; a female
      monarch; as, Elizabeth, queen of England; Mary, queen of
      Scots.
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            In faith, and by the heaven's quene.  --Chaucer.
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   3. A woman eminent in power or attractions; the highest of
      her kind; as, a queen in society; -- also used
      figuratively of cities, countries, etc. " This queen of
      cities." " Albion, queen of isles." --Cowper.
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   4. The fertile, or fully developed, female of social bees,
      ants, and termites.
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   5. (Chess) The most powerful, and except the king the most
      important, piece in a set of chessmen.
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   6. A playing card bearing the picture of a queen; as, the
      queen of spades.
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   Queen apple. [Cf. OE. quyne aple quince apple.] A kind of
      apple; a queening. "Queen apples and red cherries."
      --Spenser.

   Queen bee (Zool.), a female bee, especially the female of
      the honeybee. See Honeybee.

   Queen conch (Zool.), a very large West Indian cameo conch
      (Cassis cameo). It is much used for making cameos.

   Queen consort, the wife of a reigning king. --Blackstone.

   Queen dowager, the widow of a king.

   Queen gold, formerly a revenue of the queen consort of
      England, arising from gifts, fines, etc.

   Queen mother, a queen dowager who is also mother of the
      reigning king or queen.

   Queen of May. See May queen, under May.

   Queen of the meadow (Bot.), a European herbaceous plant
      (Spir[ae]a Ulmaria). See Meadowsweet.

   Queen of the prairie (Bot.), an American herb (Spir[ae]a
      lobata) with ample clusters of pale pink flowers.

   Queen pigeon (Zool.), any one of several species of very
      large and handsome crested ground pigeons of the genus
      Goura, native of New Guinea and the adjacent islands.
      They are mostly pale blue, or ash-blue, marked with white,
      and have a large occipital crest of spatulate feathers.
      Called also crowned pigeon, goura, and Victoria
      pigeon.

   Queen regent, or Queen regnant, a queen reigning in her
      own right.

   Queen's Bench. See King's Bench.

   Queen's counsel, Queen's evidence. See King's counsel,
      King's evidence, under King.

   Queen's delight (Bot.), an American plant (Stillinqia
      sylvatica) of the Spurge family, having an herbaceous
      stem and a perennial woody root.

   Queen's metal (Metal.), an alloy somewhat resembling pewter
      or britannia, and consisting essentially of tin with a
      slight admixture of antimony, bismuth, and lead or copper.


   Queen's pigeon. (Zool.) Same as Queen pigeon, above.

   Queen's ware, glazed English earthenware of a cream color.


   Queen's yellow (Old Chem.), a heavy yellow powder
      consisting of a basic mercuric sulphate; -- formerly
      called turpetum minerale, or Turbith's mineral.
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WordNet (r) 3.0 (2006):

queen regnant
    n 1: a female sovereign ruler [syn: queen, queen regnant,
         female monarch] [ant: Rex, king, male monarch]