The word good-bye is a phonological attrition of the phrase God be with ye, the latter being a way to say farewell that first appeared around the late fourteenth century. By the sixteenth century, God be with ye had phonetically reduced to God b' wi' ye, and during the early seventeenth century, it was contracted to the single word godbwye. Most etymologists think the shift to the form good-bye didn't occur until the late seventeenth or early eighteenth century, and they also believe the substitution of good for God was likely due to the influence of other popular and less formal salutational phrases such as good morning, good day, and good night. For some eighteenth-century folks, however, good-bye still seemed too stodgy for friendly or familial situations, so they sometimes jettisoned the good and simply used bye. Around 1739, the even less formal-sounding reduplication bye-bye appeared, but it would be another 255 years before Jim Carrey's Ace Ventura would turn that into the contraction b'bye.
©2019 Michael R. Gates
