A Grind

1. The act of reducing to powder, or of sharpening, by friction. Grind - Wikipedia
2. Something that has been reduced to powder, something that has been ground.
3. A specific degree of pulverization of coffee beans.
4. A tedious and laborious task. Synonym: chore
5. A grinding trick on a skateboard or snowboard.
6. (archaic, slang) One who studies hard. Synonym: swot
7. (uncountable, music) Clipping of grindcore (“subgenre of heavy metal”).
8. (slang) Hustle; hard work.