A magical phrase used to open otherwise impenetrable passageways.
The origin of this phrase has nothing to do with the sesame plant or seed. The phrase was created when a man with a thick Italian accent said "Open Says Me", which was misinterpreted and became "Open Sesame".
Chris: How are we going to get in, the door is locked?
Giavonna: Open Sesame (open says-a-me).
Chris: It's open. I guess it wasn't locked.