mastery

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Possession of consummate skill.
2. n. The status of master or ruler; control: mastery of the seas.
3. n. Full command of a subject of study: Her mastery of economic theory impressed the professors.

Century Dictionary and Cyclopedia

1. n. The state of being a master; power of command or control; rule; dominion; sway.
2. n. Ascendancy in war or in competition; the upper hand; superiority; preëminence.
3. n. Expert knowledge or skill; power of using or exercising; dexterity: as, the mastery of an art or science.
4. n. Masterly attainment; the gaining of mastership.
5. n. A contest for superiority.
6. n. A masterly operation or act; a triumph of skill.
7. n. The finding of the magisterium or philosopher's stone; also, the stone itself.

Wiktionary

1. n. The position or authority of a master; dominion; command; supremacy; superiority.
2. n. Superiority in war or competition; victory; triumph; preeminence.
3. n. obsolete Contest for superiority.
4. n. obsolete A masterly operation; a feat.
5. n. obsolete The philosopher's stone.
6. n. The act or process of mastering; the state of having mastered; expertise.

GNU Webster's 1913

1. n. The position or authority of a master; dominion; command; supremacy; superiority.
2. n. Superiority in war or competition; victory; triumph; preëminence.
3. n. obsolete Contest for superiority.
4. n. obsolete A masterly operation; a feat.
5. n. obsolete the philosopher's stone.
6. n. The act process of mastering; the state of having mastered.

WordNet 3.0

1. n. great skillfulness and knowledge of some subject or activity
2. n. power to dominate or defeat
3. n. the act of mastering or subordinating someone