Etymology tree Proto-Indo-European *dwóh₁ Proto-Indo-European *d(w)is- Proto-Italic *dis- Latin dis- Old French des-bor. ▲ Latin dis-bor. Middle English dis- English dis- Proto-Indo-European *lewbʰ-der. Proto-Germanic *laubō Proto-West Germanic *laubu Old English lēafa Middle English bileve English belief English disbelief From dis- + belief.