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 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.

(film) A master shot in which the camera moves relative to the performance.

(education) A class, typically in a performing art such as music or drama, in which a teacher listens to and critiques the performance of individual students, one at a time, while the other students look on.

(military, US) A non-commissioned officer in the United States Army, ranking above sergeant first class and below sergeant major; equal in grade and pay to a first sergeant.

A postgraduate degree which aims to assist students in developing a mastery for a particular academic field or profession.

A large four-masted sailboat.