Amelioration :: Amelioration (n.) The act of ameliorating, or the state of being ameliorated; making or becoming better; improvement; melioration..
Ameliorative :: Ameliorative (a.) Tending to ameliorate; producing amelioration or improvement; as, ameliorative remedies, efforts..
Melioration :: Melioration (n.) The act or operation of meliorating, or the state of being meliorated; improvement..