Open Sesame is a phrase from the story of Ali Baba and the Forty Thieves, which is part of the One Thousand and One Nights collection of Middle Eastern folk tales. The phrase is used to open a door that is magically sealed shut. In the story, Ali Baba uses the phrase to open a secret door in a mountain, allowing him to access the hidden treasure of the Forty Thieves. The crossword solutions for Open Sesame are KEY, which is an object used to open locks.