The Collaborative International Dictionary of English v.0.48:

Loggerhead \Log"ger*head`\, n. [Log + head.]
   1. A blockhead; a dunce; a numskull. --Shak. Milton.
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   2. A spherical mass of iron, with a long handle, used to heat
      tar.
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   3. (Naut.) An upright piece of round timber, in a whaleboat,
      over which a turn of the line is taken when it is running
      out too fast. --Ham. Nav. Encyc.
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   4. (Zool.) A very large marine turtle (Thalassochelys
      caretta syn. Thalassochelys caouana), common in the
      warmer parts of the Atlantic Ocean, from Brazil to Cape
      Cod; -- called also logger-headed turtle.
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   5. (Zool.) An American shrike (Lanius Ludovicianus),
      similar to the butcher bird, but smaller. See Shrike.
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   To be at loggerheads, To fall to loggerheads, or To go
   to loggerheads, to quarrel; to be at strife. --L' Estrange.
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The Collaborative International Dictionary of English v.0.48:

Steamer \Steam"er\ (-[~e]r), n.
   1. A vessel propelled by steam; a steamship or steamboat.
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   2. A steam fire engine. See under Steam.
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   3. A road locomotive for use on common roads, as in
      agricultural operations.
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   4. A vessel in which articles are subjected to the action of
      steam, as in washing, in cookery, and in various processes
      of manufacture.
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   5. (Zool.) The steamer duck.
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   Steamer duck (Zool.), a sea duck (Tachyeres cinereus),
      native of Patagonia and Terra del Fuego, which swims and
      dives with great agility, but which, when full grown, is
      incapable of flight, owing to its very small wings. Called
      also loggerhead, race horse, and side-wheel duck.
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WordNet (r) 3.0 (2006):

loggerhead
    n 1: a stupid person; these words are used to express a low
         opinion of someone's intelligence [syn: dunce,
         dunderhead, numskull, blockhead, bonehead,
         lunkhead, hammerhead, knucklehead, loggerhead,
         muttonhead, shithead, dumbass, fuckhead]
    2: very large carnivorous sea turtle; wide-ranging in warm open
       seas [syn: loggerhead, loggerhead turtle, Caretta
       caretta]