amelioration (n.)

1650s, "a making or becoming better," from French amélioration, from Old French ameillorer (12c.), from a "to" (see ad-) + meillior (Modern French meìlleur) "to better, repair, improve," from Late Latin meliorare "improve," from Latin melior "better," perhaps originally "stronger," from PIE root *mel- (2) "strong, great."