The Collaborative International Dictionary of English v.0.48:

Graal \Graal\ (gr[=a]l), n.
   See Grail, a dish.
   [1913 Webster]

The Free On-line Dictionary of Computing (30 December 2018):

GRAAL

   ("Grail") General Recursive Applicative and Algorithmic
   Language.  FP with polyadic combinators.  "Graal: A Functional
   Programming System with Uncurryfied Combinators and its
   Reduction Machine", P. Bellot in ESOP 86, G. Goos ed, LNCS
   213, Springer 1986.