The Collaborative International Dictionary of English v.0.48:

Dike \Dike\, v. t. [imp. & p. p. Diked; p. pr. & vb. n.
   Diking.] [OE. diken, dichen, AS. d[imac]cian to dike. See
   Dike.]
   1. To surround or protect with a dike or dry bank; to secure
      with a bank.
      [1913 Webster]

   2. To drain by a dike or ditch.
      [1913 Webster]