The Collaborative International Dictionary of English v.0.48:

Egg \Egg\, v. t. [imp. & p. p. Egged; p. pr. & vb. n.
   Egging.] [OE. eggen, Icel. eggja, fr. egg edge. ??. See
   Edge.]
   To urge on; to instigate; to incite?
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         Adam and Eve he egged to ill.            --Piers
                                                  Plowman.
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         [She] did egg him on to tell
         How fair she was.                        --Warner.
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