Gastronome \GAS-truh-nohm\ , noun;
1. A connoisseur of good food and drink
This word is first attested in 1823 and comes from French gastronome, a back formation of gastronomie. The alternative form, gastronomer dates to the 1820's.
Gastronomie is the forebear of gastronomy, which is first attested in English is 1814. The French word was coined in 1800 by Joseph de Berchoux in the title of a poem on good living. It was taken from the word Gastrologia, which is the title of a lost poem of antiquity that was quote by Athenaeus. It is a combination of gaster + nomos ("stomach" + "arranging, regulating").
For the record, that gaster + nomos thing was kind of confusing, so if I'm wrong let me know!
Today's word and the first definition were both taken from Dictionary.com's 'Word of the Day' for Friday, March 4
Etymologies come from the Oxford English Dictionary and/or Etymonline.com