masterpiece [masterpieces](piece of work that has been given much critical praise) noun [UK: ˈmɑːst.ə.piːs] [US: ˈmæst.r̩.ˌpis]It'll be a masterpiece! = Sarà un capolavoro!
masterwork [masterworks](piece done to be ranked a master) noun [UK: ˈmɑːst.ə.wɜːk] [US: ˈmæst.r̩.wɝːk]