knuckle down (verb)

1. She knuckled down and worked tirelessly to meet the deadline for the fashion show, just like a slave to her craft.

2. The protagonist in the horror movie had to knuckle down and confront her deepest fears in order to survive.

3. The hero knuckled down and faced the mythical creature, battling it with all his might to save the village.

4. The architect knuckled down and meticulously planned every detail of the building, working like a slave to create a masterpiece.