The phrase "study at atheist" refers to someone who is exploring atheism or seeking to learn more about it. Synonyms for this phrase could include terms like "researching atheism," "exploring atheistic beliefs," "investigating atheism," or "learning about atheism." Other related phrases might include "delving into atheism," "immersing oneself in the study of atheism," or "seeking knowledge about atheism." Whatever terminology one uses, the idea is the same: the individual is engaging in a process of inquiry and education in order to better understand atheism and its philosophical, ethical, and social implications.