The Collaborative International Dictionary of English v.0.48:

Clownish \Clown"ish\, a.
   Of or resembling a clown, or characteristic of a clown;
   ungainly; awkward. "Clownish hands." --Spenser. "Clownish
   mimic." --Prior. -- Clown"ish*ly, adv.

   Syn: Coarse; rough; clumsy; awkward; ungainly; rude; uncivil;
        ill-bred; boorish; rustic; untutored.
        [1913 Webster]