incertitude (n.)youdaoicibaDictYouDict[incertitude 词源字典]
mid-15c., "variability," from Middle French incertitude (14c.), from Late Latin incertitudinem (nominative incertitudo); see certitude. Incertain "uncertain" and incertainty "uncertainty" also were living words in Middle English.[incertitude etymology, incertitude origin, 英语词源]