"Study at guess" essentially means to study without certainty or without a clear idea of what to focus on. Some synonyms for this phrase could include studying haphazardly, studying randomly, or studying aimlessly. Other synonyms for the word "study" itself might include researching, reviewing, examining, exploring, or analyzing. It's important to identify the right synonym for the context in which you'll be using the word, and to take the time to understand specific nuances and shades of meaning that might be associated with each choice. Whether you're a student or a professional, knowing how to communicate information in an effective and precise way is an essential skill.