Source : Webster's Revised Unabridged Dictionary (1913)

Ruttier \Rut"ti*er\, n. [F. routier, fr. route a road. See
   {Route}.]
   A chart of a course, esp. at sea. [Obs.]

Source : WordNet®

rutty
     adj : full of ruts; "rutty farm roads" [syn: {rutted}]
     [also: {ruttiest}, {ruttier}]

ruttier
     See {rutty}