The Collaborative International Dictionary of English v.0.48:

Azure \Az"ure\ (?; 277), a. [F. & OSp. azur, Sp. azul, through
   Ar. from Per. l[=a]jaward, or l[=a]juward, lapis lazuli, a
   blue color, l[=a]jaward[imac], l[=a]juward[imac], azure,
   cerulean, the initial l having been dropped, perhaps by the
   influence of the Ar. azr-aq azure, blue. Cf. G. lasur,
   lasurstein, azure color, azure stone, and NL. lapis lazuli.]
   Sky-blue; resembling the clear blue color of the unclouded
   sky; cerulean; also, cloudless.
   [1913 Webster]

   Azure stone (Min.), the lapis lazuli; also, the lazulite.
      [1913 Webster]