\Mas"ter*ly\, 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. ``A wise and masterly
   inactivity.'' --Sir J. Mackintosh.
2. Imperious; domineering; arbitrary.

\Mas"ter*ly\, adv.
With the skill of a master.
      Thou dost speak masterly.                --Shak.