Gad \Gad\, n. [OE. gad, Icel. gaddr goad, sting; akin to Sw.
   gadd sting, Goth. gazds, G. gerte switch. See Yard a
   measure.]
   1. The point of a spear, or an arrowhead.
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   2. A pointed or wedge-shaped instrument of metal, as a steel
      wedge used in mining, etc.
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            I will go get a leaf of brass,
            And with a gad of steel will write these words.
                                                  --Shak.
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   3. A sharp-pointed rod; a goad.
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   4. A spike on a gauntlet; a gadling. --Fairholt.
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   5. A wedge-shaped billet of iron or steel. [Obs.]
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            Flemish steel . . . some in bars and some in gads.
                                                  --Moxon.
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   6. A rod or stick, as a fishing rod, a measuring rod, or a
      rod used to drive cattle with. [Prov. Eng. Local, U.S.]
      --Halliwell. Bartlett.
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   Upon the gad, upon the spur of the moment; hastily. [Obs.]
      "All this done upon the gad!" --Shak.
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