* Literal uses:
* He knuckled down to his work and finished the project early.
* The boxer landed a powerful punch, cracking his opponent's knuckle bone.
* She cracked her knuckles loudly, which always annoyed her coworkers.
* The old book's pages were worn thin, with the knuckles of countless readers imprinted on them.
* Figurative uses:
* The team knuckled under to the pressure and lost the game.
* He knuckled down and learned how to use the software.
* The detective knuckled down to find the truth.
* She knuckled under to her boss's demands.
These examples demonstrate various ways the word "knuckle" can be used, both literally and figuratively.