The phrase "hadst one nose grindstone" is an old English idiom that means to be focused and hardworking. If you're looking for synonyms, here are a few options to use instead: diligent, industrious, assiduous, hardworking, persevering, committed, dedicated, disciplined, focused, tenacious, and persistent. Using any of these words in place of "hadst one nose grindstone" will help to convey the same meaning while keeping your writing fresh and engaging. Whether you're writing an essay, report, or creative piece, using these synonyms will allow you to express your ideas accurately and effectively.