Source : Webster's Revised Unabridged Dictionary (1913)

Sheepish \Sheep"ish\, a.
   1. Of or pertaining to sheep. [Obs.]

   2. Like a sheep; bashful; over-modest; meanly or foolishly
      diffident; timorous to excess.

            Wanting change of company, he will, when he comes
            abroad, be a sheepish or conceited creature.
                                                  --Locke.
      -- {Sheep"ish*ly}, adv. -- {Sheep"ish*ness}, n.

Source : WordNet®

sheepishness
     n : feeling embarrassed about yourself [syn: {shamefacedness}]