The Collaborative International Dictionary of English v.0.48:

Obese \O*bese"\ a. [L. obesus eaten away, lean; also, that has
   eaten itself fat, fat, stout, p. p. of obedere to devour; ob
   (see Ob-) + edere to eat. See Eat.]
   Excessively corpulent; fat; fleshy.
   [1913 Webster]

WordNet (r) 3.0 (2006):

obese
    adj 1: excessively fat; "a weighty man" [syn: corpulent,
           obese, weighty, rotund]