noun

• (chess) A player of the highest rank, as determined by FIDE, with an Elo rating of at least 2500.
• A master in a field, whose skills or accomplishments exceed those of other masters.
• (chess, historical) Short for Grandmaster of the Soviet Union; USSR champion.
• Alternative spelling of Grandmaster [(chess) A player of the highest rank, as determined by FIDE, with an Elo rating of at least 2500.]