1 noun RELthe Holy Grailan Soitheach Naofa2 (also holy grail) nounthe holy grail of our research is to cure diseasegalair a leigheas an sprioc atá againn leis an taighde seosales are the holy grail of advertising companiesdíolacháin an chloch is mó ar phaidrín lucht fógraíochta