work like a horse

willing horse

One who readily performs hard work or who voluntarily tolerates an adv…

slug away

To work very hard (at); to toil

work like a dog

To work very hard.

hard at work

Labouring with great effort and diligence; working hard.

blood, sweat and tears

A person's determination and hard work.

bust ass

To work hard, especially when trying to achieve a goal.