The phrase "by the sweat of your brow" typically means that someone has worked hard and put in a lot of effort to achieve something. There are several other synonyms that can be used in place of this phrase such as "hard work pays off", "labour of love", "toil and sweat", and "grindstone". Each of these synonyms conveys the concept of putting in effort and hard work to achieve something worthwhile. These phrases can be used in various contexts such as discussing achievements in sports, completing a challenging project at work, or building a successful small business. Ultimately, regardless of the context, these synonyms emphasize the value of hard work and dedication.