/grayl/ , n.
1. ( usually cap. ) Also called Holy Grail . a cup or chalice that in medieval legend was associated with unusual powers, esp. the regeneration of life and, later, Christian purity, and was much sought after by medieval knights: identified with the cup used at the Last Supper and given to Joseph of Arimathea.
2. ( sometimes cap. ) Informal. any greatly desired and sought-after objective; ultimate ideal or reward.
[ 1300-50; ME graiel, graile, etc. grahel, grayel, OF gräel, grel gradalis platter, of uncert. orig. ]