1 [count] : someone who has control or power over others: such as a : someone (especially a man) who has a servant or slave ▪ As a slave he was required to do his master's bidding without question. b : someone (especially a man) who owns a pet (such as a dog) ▪ The dog was always obedient to its master. c formal : the male head of a household ▪ the master and mistress of the house d : a man who is in charge of the people on a ship ▪ a ship's master
2 [count] : a person who has control of something —usually + of ▪ He was the master of his feelings. [=he was able to control his own feelings] ▪ She proved herself (to be) master of the situation. ▪ We are the masters of our own destiny.
3 [count] : a person who has become very skilled at doing something ▪ She is a master of her craft. ▪ a chess master ▪ a Dutch master [=one of the great Dutch painters of the past] —often + at ▪ He is a master at manipulating people. —see also grand master, past master
4 a [count] old-fashioned : a male teacher —see also headmaster, schoolmaster b Master —used as a title for the male head of certain British colleges ▪ He was Master of Balliol.
5 [count] : a person who has received a master's degree ▪ a master of arts
6 [count] : an original version of something (such as a recording) from which copies can be made
7 Master formal + old-fashioned —used as a title for a boy who is too young to be called Mister ▪ Master Timothy