"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.