something that no one can be certain about What will happen next is anybody's guess.
a guess that is based on some degree of knowledge, and is therefore likely to be correct
used to tell someone that you do not know any more about a subject than the person that you are talking to does “Who's going to win?” “Your guess is as good as mine.”
to make a mistake Unless I miss my guess, your computer needs a new hard drive. If you miss your guess, you lose 10 points.
Check pronunciation: guess