The Collaborative International Dictionary of English v.0.48:

Overeat \O`ver*eat"\, v. t. & i.
   1. To gnaw all over, or on all sides. [Obs.] --Shak.
      [1913 Webster]

   2. To eat to excess; -- sometimes with a reflexive; as, she
      overate at the party and spent the next week dieting.
      [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

overeat
    v 1: overeat or eat immodestly; make a pig of oneself; "She
         stuffed herself at the dinner"; "The kids binged on ice
         cream" [syn: gorge, ingurgitate, overindulge, glut,
         englut, stuff, engorge, overgorge, overeat,
         gormandize, gormandise, gourmandize, binge, pig
         out, satiate, scarf out]

The Devil's Dictionary (1881-1906):

OVEREAT, v.  To dine.

    Hail, Gastronome, Apostle of Excess,
    Well skilled to overeat without distress!
    Thy great invention, the unfatal feast,
    Shows Man's superiority to Beast.
                                                             John Boop