猜测 (cāi cè) is a more formal, reasoned kind of guessing, often based on incomplete evidence or reasoning. Compared to the everyday verb 猜 (cāi), 猜测 implies a thoughtful conjecture, not a wild guess. It is similar to 推测 (tuī cè) but 推测 focuses more on inferring from evidence, while 猜测 can be more speculative.