Sesame

ses'a-me, a short, annual herb, India to Egypt, the small seeds of which yield half their weight of oil-of-sesame. It is a sweet, agreeable substitute for olive oil and is much in demand in the Orient as a substitute for our lard, butter, and sirup. Sesame oil is an ointment for the face. As an article of food it has the additional recommendation of keeping for years without becoming rancid. See Arabian Nights

Open sesame, the charm by which the door of the robbers' dungeon in the tale of Ali Baba and the Forty Thieves (in the Arabian Nights' Entertainments) flew open; hence, a specific for gaining entrance into any place, or means of exit from it.-Century Dictionary.