Source : Webster's Revised Unabridged Dictionary (1913)

Cerulean \Ce*ru"le*an\, a. [L. caeruleus.]
   Sky-colored; blue; azure. --Cowper.

         Blue, blue, as if that sky let fall

         A flower from its cerulean wall.         --Bryant.

Source : WordNet®

cerulean
     adj : of a deep somewhat purplish blue color similar to that of a
           clear October sky; "October's bright blue weather"
           [syn: {azure}, {sky-blue}, {bright blue}]

cerulean
     n : a light shade of blue [syn: {azure}, {sapphire}, {lazuline},
          {sky-blue}]