with out consulting a dictionary, i would say GRAIL is a word the refers to a wine goblet, specifically the one used by jesus at the last supper.

(which is why you almost always see grail paired with holy.)

the existence of the goblet jesus used is mythical--and in some myths (english ones) its to be found in england. in the indiana jones movie, the grail was to be found in what looked like etheopia, (or north west africa somewhere).

there are many myths associated with the holy grail, (healing powers, etc).