The Collaborative International Dictionary of English v.0.48:

Mog \Mog\, v. t. [imp. & p. p. Mogged; p. pr. & vb. n.
   Mogging.] [Etym. unknown.]
   To move away; to go off. [Prov. Eng. or Local, U. S.]
   [Webster 1913 Suppl.]