N-UNCOUNT （干粗活用的）力气，蛮力；(费力的)擦拭 People use elbow grease to refer to the strength and energy that you use when doing physical work like rubbing or polishing. （干粗活用的）力气，蛮力；(费力的)擦拭 [informal]
It took a considerable amount of polish and elbow grease before the brass shone like new.