The Collaborative International Dictionary of English v.0.48:

Whimsey \Whim"sey\, Whimsy \Whimsy\, n.; pl. Whimseysor
   Whimsies. [See Whim.]
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   1. A whim; a freak; a capricious notion, a fanciful or odd
      conceit. "The whimsies of poets and painters." --Ray.
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            Men's folly, whimsies, and inconstancy. --Swift.
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            Mistaking the whimseys of a feverish brain for the
            calm revelation of truth.             --Bancroft.
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   2. (Mining) A whim.
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