n., adj., & v.
n. 1 a a person having control of persons or things. b an employer. c a male head of a household (master of the house). d the owner of a dog, horse, etc. e the owner of a slave. f Naut. the captain of a merchant ship. g Hunting the person in control of a pack of hounds etc. 2 a male teacher or tutor, esp. a schoolmaster. 3 a the head of a college, school, etc. b the presiding officer of a livery company, Masonic lodge, etc. 4 a person who has or gets the upper hand (we shall see which of us is master). 5 a person skilled in a particular trade and able to teach others (often attrib.: master carpenter). 6 a holder of a university degree orig. giving authority to teach in the university (Master of Arts; Master of Science). 7 a a revered teacher in philosophy etc. b (the Master) Christ. 8 a great artist. 9 Chess etc. a player of proved ability at international level. 10 an original version (e.g. of a film or gramophone record) from which a series of copies can be made. 11 (Master) a a title prefixed to the name of a boy not old enough to be called Mr (Master T. Jones; Master Tom). b archaic a title for a man of high rank, learning, etc. 12 (in England and Wales) an official of the Supreme Court. 13 a machine or device directly controlling another (cf. SLAVE). 14 (Master) a courtesy title of the eldest son of a Scottish viscount or baron (the Master of Falkland).
adj. 1 commanding, superior (a master spirit). 2 main, principal (master bedroom). 3 controlling others (master plan).
v.tr. 1 overcome, defeat. 2 reduce to subjection. 3 acquire complete knowledge of (a subject) or facility in using (an instrument etc.). 4 rule as a master. be master of 1 have at one's disposal. 2 know how to control. be one's own master be independent or free to do as one wishes. make oneself master of acquire a thorough knowledge of or facility in using. Master Aircrew an RAF rank equivalent to warrant-officer. master-at-arms (pl. masters-at-arms) the chief police officer on a man-of-war or a merchant ship. master-class a class given by a person of distinguished skill, esp. in music. master-hand 1 a person having commanding power or great skill. 2 the action of such a person. master-key a key that opens several locks, each of which also has its own key. master mariner 1 the captain of a merchant ship. 2 a seaman certified competent to be captain. master mason 1 a skilled mason, or one in business on his or her own account. 2 a fully qualified Freemason, who has passed the third degree. Master of Ceremonies see CEREMONY. Master of the Rolls (in England and Wales) a judge who presides over the Court of Appeal and was formerly in charge of the Public Record Office. master-stroke an outstandingly skilful act of policy etc. master-switch a switch controlling the supply of electricity etc. to an entire system. master touch a masterly manner of dealing with something. master-work a masterpiece. masterdom n. masterhood n. masterless adj.
[ OE mgester (later also f. OF maistre) f. L magister, prob. rel. to magis more ]