(Ireland, colloquial, plurale tantum) tutoring; extra lessons in a specific subject outside of school hours. Grinds are often given by private individuals or firms, and might not be provided by the school.
The day had arrived with more bumps and grinds than a burlesque matron.
God for him is the creator and ruler of the world, but hardly more; he is the master of a vast machine that grinds out human destinies without sympathy with man and without visible regard for what man deems justice - a being to be acknowledged as lord, not one to be loved.
One local restaurant grinds the meat fresh daily for the hamburgers they serve.