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]

The Collaborative International Dictionary of English v.0.48:

Kingly \King"ly\, adv.
   In a kingly or kinglike manner. --Shak.
   [1913 Webster]

         Low bowed the rest; he, kingly, did but nod. --Pore.
   [1913 Webster]

   Note: Although this citation, one from Paradise Lost, and one
         from Shakespeare's ll4th Sonnet are given by
         lexicographers as examples of adverbial use, it is by
         no means clear that the word is not an adjective in
         each instance.
         [1913 Webster]

WordNet (r) 3.0 (2006):

kingly
    adj 1: having the rank of or resembling or befitting a king;
           "symbolizing kingly power"; "the murder of his kingly
           guest" [syn: kingly, kinglike]

Moby Thesaurus II by Grady Ward, 1.0:

54 Moby Thesaurus words for "kingly":
   aristocratic, august, chivalrous, courtly, dignified, ducal,
   dynastic, exalted, genteel, gentle, gentlemanlike, gentlemanly,
   grand, grave, high, imperatorial, imperatorious, imperial,
   imperious, imposing, kinglike, knightly, ladylike, lordly,
   magisterial, majestic, masterful, monarchal, monarchial, monarchic,
   monarchical, noble, of gentle blood, of rank, patrician, powerful,
   princelike, princely, puissant, purple, queenlike, queenly,
   quite the lady, regal, royal, sedate, sober, solemn, sovereign,
   stately, statuesque, titled, venerable, worthy