Elbow grease

Elbow grease is an idiom that is older than you may think. An idiom is  a word, group of words or phrase that has a figurative meaning that is not easily deduced from literal meaning. We will look at the meaning of the term elbow grease, where it came from and some examples of its […]
from Grammarist
http://grammarist.com/usage/elbow-grease/