(nautical) A seaman who has qualified to be a captain of a merchant ship

plural of master mariner

plural of game master

plural of dungeon master

(role-playing games) A person conducting a role-playing game, generally responsible for controlling all beings and processes other than the players, either individually or as part of a team.

(role-playing games) A game master in Dungeons & Dragons games.

plural of Master of the Universe

(religion) God / (idiomatic) A powerful person. / (idiomatic, finance, business) A highly successful business person.

The leading entity; the most important person, the controlling figure.

plural of Master Cube