The Collaborative International Dictionary of English v.0.48:

Spet \Spet\, v. t. [AS. sp?tan. See Spit.]
   To spit; to throw out. [Obs.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Spet \Spet\, n.
   Spittle. [Obs.]
   [1913 Webster]