C15: from Old French Saint Graal. See saint, Holy Grail
Holy Grail in British English
noun
1.
a. Also called: Grail, Sangraal
(in medieval legend) the bowl used by Jesus at the Last Supper. It was allegedly brought to Britain by Joseph of Arimathea, where it became the quest of many knights
b.
(in modern spirituality) a symbol of the spiritual wholeness that leads a person to union with the divine
2. informal
any desired ambition or goal
the Holy Grail of infrared astronomy
Word origin
C14 grail from Old French graal, from Medieval Latin gradālis bowl, of unknown origin