elbow grease

Elbow grease is the hard physical work that's often required to get a difficult task done. It might take some serious elbow grease, but you can get your house painted by the end of the week.

You can use the idiom elbow grease when you talk about working up a sweat or putting in some manual labor to complete a task. If your little brother complains that mowing the lawn is too hard, you might say, "It just takes a little elbow grease!" The English poet Andrew Marvell used the word in 1672, and in 1699 it appeared in the "New Dictionary of the Canting Crew" with the definition "a derisory Term for Sweat."