Rasper is a word used to describe something that rubs or scrapes harshly against another surface. Some synonyms for Rasper include abrasive, grater, file, rough, coarse, scratchy, rasping, and sandpaper. These words capture the same meaning as Rasper but with slightly different connotations. Abrasive, for instance, suggests a roughness that can wear something down. Grater tends to imply a tool that shreds things. Similarly, file implies a tool used to smooth and shape hard materials like metal or wood. All these words are useful alternatives for Rasper depending on the context in which they are used.