Toils away is a phrase that implies hard work or effort. There are several synonyms that can be used in place of this phrase. One option is "labors," which can refer to physical or mental work. Another synonym is "works diligently," which suggests a focused and determined effort. "Strives" is a word that indicates someone is working towards a goal. "Slogs" suggests a difficult and arduous task. "Grinds" can refer to working through something difficult or tedious. "Sweats" implies exertion and physical effort. "Plods" suggests steady and methodical work. No matter which synonym is used, the idea is that the person is putting in substantial effort towards a task or project.