do the unthinkable

To do something that would never be expected to be done, especially something particularly unorthodox or extreme. Lena was a stellar student until she did the unthinkable and dropped out of school. If they have any chance of winning this game, they're going to have to do the unthinkable and pull their star quarterback. In my family of doctors, I did the unthinkable when I moved to Hollywood to pursue an acting career.

See also:

a whole different animal
a whole different ball of wax
a whole different beast
(something) to go on
a fast talker
a/the feel of (something)
(I) wouldn't (do something) if I were you
a straw will show which way the wind blows
a casualty of (something)
a crack at (someone or something)

All content on this website, including dictionary, thesaurus, literature, geography, and other reference data is for informational purposes only. This information should not be considered complete, up to date, and is not intended to be used in place of a visit, consultation, or advice of a legal, medical, or any other professional.