Masterly

Mas·ter·ly

Masterly

a.
  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.
  2. Imperious; domineering; arbitrary.

Masterly

adv.
  1. With the skill of a master.
    Thou dost speak masterly.