Holy Grail

The Holy Grail is a legendary Christian relic, often described as the cup Jesus used at the Last Supper and Joseph of Arimathea used to catch his blood at the Crucifixion, becoming a central quest in Arthurian legend for its miraculous healing powers and association with divine grace. Beyond its religious origins, "holy grail" metaphorically refers to any elusive, highly sought-after goal or object, like sustained nuclear fusion or finding Earth-like exoplanets.