A person with an extraordinary intellect or skill that is markedly superior to his or her peers. / A person responsible for the highest level of planning and execution of a major operation.

To act in the role of mastermind.

(especially Nazism) A race of people who are superior to others.

The position or authority of a master; dominion; command; supremacy; superiority. / Superiority in war or competition; victory; triumph; preeminence.

A key designed to open a set of several locks; a passkey. / (figuratively) Any tool or technique that can solve many types of difficulty.

A skilled and experienced tradesman, especially one who has submitted a masterpiece to his guild.

(humorous) Respectful term of address for an expert in a particular field.

A piece done to prove possession of skill sufficient to be ranked a master. / A piece of quality, indicative of having been made by a master; a masterpiece. / (obsolete) An act of primary importance.

A postgraduate degree usually in a non-science subject. / A person holding such a degree.

A room in a house, in which the head of the household sleeps, typically larger and better furnished than other bedrooms.