Eupeptic first appeared around 1700 and was probably created from eupepsia, a word meaning "good digestion." (Eupepsia was cooked up from eu-, meaning "good," and -pepsia, meaning "digestion," ingredients that are ultimately of Greek origin.) It seems reasonable that good digestion might enhance one's outlook on life - and indeed, eupeptic can suggest a happy frame of mind as well as a happy digestive system. Along similar lines, someone with poor digestion might be cranky, and the antonymous counterparts of eupeptic and eupepsia - dyspeptic and dyspepsia - can suggest either indigestion or ill humor.