"Toiled away" is a phrase that refers to working hard and persistently on a task. There are several synonyms for this phrase such as "labored diligently," "slogged," "struggled through," "exerted oneself," "worked tirelessly," "persevered," "pushed through," "grinded," "slaved away," "laboured," "strived," and "pursued with determination." These synonyms all suggest a great deal of effort and dedication to completing a task. Using these synonyms can help to avoid repetition in writing or speech and add variety and depth to one's vocabulary. Ultimately, they convey the idea of working hard with commitment and focused determination to achieve a goal.