The Collaborative International Dictionary of English v.0.48:

Whet \Whet\, n.
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   1. The act of whetting.
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   2. That which whets or sharpens; esp., an appetizer. "Sips,
      drams, and whets." --Spectator.
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   Whet slate (Min.), a variety of slate used for sharpening
      cutting instruments; novaculite; -- called also whetstone
      slate, and oilstone.
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The Collaborative International Dictionary of English v.0.48:

Whet \Whet\, v. t. [imp. & p. p. Whetted; p. pr. & vb. n.
   Whetting.] [AS. hwettan; akin to D. wetten, G. wetzen, OHG.
   wezzen, Icel. hvetja, Sw. v[aum]ttja, and AS. hw[ae]t
   vigorous, brave, OS. hwat, OHG. waz, was, sharp, Icel. hvatr,
   bold, active, Sw. hvass sharp, Dan. hvas, Goth. hwassaba
   sharply, and probably to Skr. cud to impel, urge on.]
   [1913 Webster]
   1. To rub or on with some substance, as a piece of stone, for
      the purpose of sharpening; to sharpen by attrition; as, to
      whet a knife.
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            The mower whets his scythe.           --Milton.
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            Here roams the wolf, the eagle whets his beak.
                                                  --Byron.
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   2. To make sharp, keen, or eager; to excite; to stimulate;
      as, to whet the appetite or the courage.
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            Since Cassius first did whet me against Caesar,
            I have not slept.                     --Shak.
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   To whet on, To whet forward, to urge on or forward; to
      instigate. --Shak.
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WordNet (r) 3.0 (2006):

whet
    v 1: make keen or more acute; "whet my appetite" [syn: whet,
         quicken]
    2: sharpen by rubbing, as on a whetstone