master

A combatant who is able to defeat rivals.

An officer who is licensed to command a merchant ship.

An artist of consummate skill.

“a master of the violin”

“one of the old masters”

Directs the work of others.

Someone who holds a master's degree from academic institution.

An authority qualified to teach apprentices.

Key that secures entrance everywhere.

An original creation (i.e., an audio recording) from which copies can be made.

Presiding officer of a school.

A person who has general authority over others.

Have a firm understanding or knowledge of; be on top of.

Get on top of; deal with successfully.

Be or become completely proficient or skilled in.

“She mastered Japanese in less than two years”

Have dominance or the power to defeat over.

“Her pain completely mastered her”

“The methods can master the problems”

Most important element.

“the master bedroom”

“a master switch”