To Master

1. (intransitive) To be a master.
2. (transitive) To become the master of; to subject to one's will, control, or authority; to conquer; to overpower; to subdue.
3. (transitive) To learn to a high degree of proficiency.
4. (transitive, obsolete) To own; to possess.
5. (transitive, especially of a musical performance) To make a master copy of.
6. (intransitive, usually with in) To earn a Master's degree