wild guess

Just a wild guess, but I have a hunch that Kirsten Kukowski is glad Tuesday is over.

Actually, I was hired as an experiment—or, rather, as the result of a wild guess that happened to work.

With Southern rashness, Coste met the difficulty of authorship with a wild guess.

This etymology, for a long time regarded as a wild guess, has been shewn by recent research to be most probably correct.

If they carried Verbeck away, it's a wild guess where they took him.

Nor could he even venture a wild guess at what kind of danger Chahda faced.