grail

noun
1
the cup or bowl believed to have been used by Jesus Christ before he died, that became a holy thing that people wanted to find
جام مقدس, کاسه مقدس, پیاله مقدس
2
a thing that you try very hard to find or achieve, but never will
هدف دست‌نیافتنی, خواسته‌ی آرمانی, آرمان بلندپروازانه