n Someone who has control over something or someone.
n The owner of an animal or slave.
n (nautical) The captain of a merchant ship; a master mariner.
n (dated) A male head of a household.
n Someone who employs others.
n An expert at something.
n A tradesman who is qualified to teach apprentices.
n (dated) A male schoolteacher.
n A skilled artist.
n (dated) A man or a boy; mister. See Master.
n A master's degree; a type of postgraduate degree, usually undertaken after a bachelor degree.
n A person holding such a degree.
n The original of a document or of a recording.
n (film) The primary wide shot of a scene, into which the closeups will be edited later.
n (law) A parajudicial officer (such as a referee, an auditor, an examiner, or an assessor) specially appointed to help a court with its proceedings.
n (engineering, computing) A device that is controlling other devices or is an authoritative source.
n (Freemasonry) A person holding an office of authority, especially the presiding officer.
n (by extension) A person holding a similar office in other civic societies.
n (BDSM) A male dominant.
adj Masterful.
adj Main, principal or predominant.
adj Highly skilled.
adj Original.
v (intransitive) To be a master.
v (transitive) To become the master of; to subject to one's will, control, or authority; to conquer; to overpower; to subdue.
v (transitive) To learn to a high degree of proficiency.
v (transitive, obsolete) To own; to possess.
v (transitive, especially of a musical performance) To make a master copy of.
v (intransitive, usually with in) To earn a Master's degree.
n (nautical, in combination) A vessel having a specified number of masts.
n Prepended to a boy's name or surname as a (now somewhat formal) form of address.
n A religious teacher, often as an honorific title.
n The title of the head of certain colleges and schools.
n A master's degree.
n A person holding a master's degree, as a title.
n The title of the eldest son of a Scots lord.
n The owner of a slave, in some literature.
n (BDSM) Used as the title of a dominant.
n (Wicca) One of the triune gods of the Horned God in Wicca alongside the Father and Sage and representing a boy or a young man
n (banking) Mastercard
n Short for master key. [A key designed to open a set of several locks; a passkey.]