supergrandmaster

noun1

1. •
   (rare) A particular grandmaster whose proficiency in chess or in general is notably greater than that of average grandmasters.

   • Hungarian supergrandmaster Lajos Portisch once gave a recital of songs on Hungarian radio; and at the Wijk aan Zee 1990 tournament sang Schubert’s ‘Winterreise’, accompanied by IM Bouwmeester. — 1993