The Collaborative International Dictionary of English v.0.48:

Bon vivant \Bon` vi`vant"\ (b[^o]N` v[-e]`v[aum]N"); pl. Bons
   vivants (-v[aum]N"z). [F. bon good + vivant, p. pr. of vivre
   to live.]
   A good fellow; a jovial companion; a free liver.
   [1913 Webster]

WordNet (r) 3.0 (2006):

bon vivant
    n 1: a person devoted to refined sensuous enjoyment (especially
         good food and drink) [syn: epicure, gourmet,
         gastronome, bon vivant, epicurean, foodie]