The Collaborative International Dictionary of English v.0.48:

Vicontiel \Vi*con"ti*el\, a. [From OE. vicounte a viscount. See
   Viscount.] (O. Eng. Law)
   Of or pertaining to the viscount or sheriff of a county.
   [1913 Webster]

   Vicontiel rents. See Vicontiels.

   Vicontiel writs, such writs as were triable in the sheriff,
      or county, court.
      [1913 Webster]

Bouvier's Law Dictionary, Revised 6th Ed (1856):

VICONTIEL. Belonging to the sheriff.