The Collaborative International Dictionary of English v.0.48:

Termagant \Ter"ma*gant\, n. [OE. Trivigant, Termagant, Termagant
   (in sense 1), OF. Tervagan; cf. It. Trivigante.]
   1. An imaginary being supposed by the Christians to be a
      Moslem deity or false god. He is represented in the
      ancient moralities, farces, and puppet shows as extremely
      vociferous and tumultous. [Obs.] --Chaucer. "And
      oftentimes by Termagant and Mahound [Mahomet] swore."
      --Spenser.
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            The lesser part on Christ believed well,
            On Termagant the more, and on Mahound. --Fairfax.
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   2. A boisterous, brawling, turbulent person; -- formerly
      applied to both sexes, now only to women.
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            This terrible termagant, this Nero, this Pharaoh.
                                                  --Bale (1543).
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            The slave of an imperious and reckless termagant.
                                                  --Macaulay.
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The Collaborative International Dictionary of English v.0.48:

Termagant \Ter"ma*gant\, a.
   Tumultuous; turbulent; boisterous; furious; quarrelsome;
   scolding. -- Ter"ma*gant*ly, adv.
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         A termagant, imperious, prodigal, profligate wench.
                                                  --Arbuthnot.
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WordNet (r) 3.0 (2006):

termagant
    n 1: a scolding nagging bad-tempered woman [syn: shrew,
         termagant]