The Collaborative International Dictionary of English v.0.48:

Inurbane \In`ur*bane"\, a. [L. inurbanus. See In- not, and
   Urbane.]
   Uncivil; unpolished; rude. Opposite of urbane. --M. Arnold.
   -- In`ur*bane"ly, adv. -- In`ur*bane"ness, n.
   [1913 Webster]