Masterly
Masterly , adjective
1.
Suitable to, or characteristic of, a master; indicating thorough knowledge or superior skill and power; showing a master's hand; as, a masterly design; a masterly performance; a masterly policy.
A wise and masterly inactivity.
2.
Imperious; domineering; arbitrary.
Masterly , adverb
With the skill of a master.
Thou dost speak masterly.