Unturned describes something that hasn't been flipped over, rotated, or examined from the other side. When you leave no stone unturned in searching for something, you check everywhere possible, turning over every rock to see what might be hiding underneath.

The word appears most often in the phrase leave no stone unturned, which means to search thoroughly and check every possibility. If you're looking for a lost library book, you might leave no stone unturned by checking your locker, your backpack, under your bed, in the car, and even back at the library itself. A detective working on a case might leave no stone unturned by interviewing every witness and examining every clue.

Outside that common phrase, you might describe a playing card as unturned if it's still face-down, or say that a page remains unturned if nobody has opened it yet. The word suggests potential or mystery: what you haven't looked at yet might contain exactly what you're searching for. When something important is at stake, like finding a missing pet or solving a difficult problem, leaving no stone unturned means refusing to give up until you've exhausted every option.