The Collaborative International Dictionary of English v.0.48:

Kingly \King"ly\, a. [Compar. Kinglier; superl. Kingliest.]
   Belonging to, suitable to, or becoming, a king;
   characteristic of, or resembling, a king; directed or
   administered by a king; monarchical; royal; sovereign; regal;
   august; noble; grand. "Kingly magnificence." --Sir P. Sidney.
   "A kingly government." --Swift. "The kingly couch." --Shak.
   [1913 Webster]

         The kingliest kings are crowned with thorn. --G.
                                                  Massey.
   [1913 Webster]

         Leave kingly backs to cope with kingly cares. --Cowper.

   Syn: Regal; royal; monarchical; imperial; august; sovereign;
        noble; splendid.

   Usage: Kingly, Regal. Kingly is Anglo-Saxon, and refers
          especially to the character of a king; regal is Latin,
          and now relates more to his office. The former is
          chiefly used of dispositions, feelings, and purposes
          which are kinglike; as, kingly sentiments; kingly
          condescension; " a kingly heart for enterprises."
          --Sir P. Sidney. The latter is oftener applied to
          external state, pomp, etc.; as, regal state, regal
          title, etc. This distinction is not observed by our
          early writers, but is gaining ground.
          [1913 Webster]