any of numerous shrubs belonging to a particular group (Azalea) of the genus Rhododendron, of the heath family, comprising species with handsome flower clusters of various colors, some of which are familiar in cultivation: the group was formerly the botanical genus Azalea but is now a horticultural classification.
any ericaceous plant of the group Azalea, formerly a separate genus but now included in the genus Rhododendron: cultivated for their showy pink or purple flowers
[C18: via New Latin from Greek, from azaleos dry; from its supposed preference for a dry situation]