ETYM Old Eng. maistre, maister, Old Fren. maistre, mestre, French maître, from Latin magister, orig. a double comparative from the root of magnus great, akin to Greek megas. Related to Maestro, Magister, Magistrate, Magnitude, Major, Mister, Mistress, Mickle.
1. One who directs the work of other; especially, one who directs slaves.
2. One who controls a domain or an activity.
3. An authority qualified to teach apprentices; SYN. professional.
4. The owner of a pet.
5. An officer who is licensed to command a merchant ship; SYN. captain, sea captain, skipper.
6. An original (audio recording) from which copies can be made; SYN. master copy, original.
7. Holds masters degree from academic institution.

1. Controlling
2. Highly skilled or proficient

1. To be or become completely proficient or skilled in; SYN. get the hang.
2. To have a firm understanding or knowledge of; be on top of; SYN. control.