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.
The kingliest kings are crowned with thorn. --G.
Leave kingly backs to cope with kingly cares. --Cowper.
Syn: Regal; royal; monarchical; imperial; august; sovereign;
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.