The Collaborative International Dictionary of English v.0.48:

Uppish \Up"pish\, a. [From Up.]
   Proud; arrogant; assuming; putting on airs of superiority.
   [Colloq.] --T. Brown. -- Up"pish*ly, adv. [Colloq.] --
   Up"pish*ness, n. [Colloq.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

uppishness
    n 1: assumption of airs beyond one's station [syn: uppityness,
         uppishness]