The Collaborative International Dictionary of English v.0.48:

Azalea \A*za"le*a\ (?; 97), n.; pl. Azaleas. [NL., fr. Gr. ?
   dry, -- so called because supposed to grow best in dry
   ground.] (Bot.)
   A genus of showy flowering shrubs, mostly natives of China or
   of North America; false honeysuckle. The genus is scarcely
   distinct from Rhododendron.
   [1913 Webster]

WordNet (r) 3.0 (2006):

azalea
    n 1: any of numerous ornamental shrubs grown for their showy
         flowers of various colors