The Collaborative International Dictionary of English v.0.48:

Thew \Thew\ (th[=u]), n.

   Note: [Chiefly used in the plural Thews (th[=u]z).] [OE.
         thew, [thorn]eau, manner, habit, strength, AS.
         [thorn]e['a]w manner, habit (cf. [thorn][=y]wan to
         drive); akin to OS. thau custom, habit, OHG. dou.
         [root]56.]
   1. Manner; custom; habit; form of behavior; qualities of
      mind; disposition; specifically, good qualities; virtues.
      [Obs.]
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            For her great light
            Of sapience, and for her thews clear. --Chaucer.
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            Evil speeches destroy good thews.     --Wyclif (1
                                                  Cor. xv. 33).
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            To be upbrought in gentle thews and martial might.
                                                  --Spenser.
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   2. Muscle or strength; nerve; brawn; sinew. --Shak.
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            And I myself, who sat apart
            And watched them, waxed in every limb;
            I felt the thews of Anakim,
            The pules of a Titan's heart.         --Tennyson.
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