The Collaborative International Dictionary of English v.0.48:

Viburnum \Vi*bur"num\, n. [L., the wayfaring tree.] (Bot.)
   A genus of shrubs having opposite, petiolate leaves and
   cymose flowers, several species of which are cultivated as
   ornamental plants, as the laurestine and the guelder-rose.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Viburnum
    n 1: deciduous or evergreen shrubs or small trees: arrow-wood;
         wayfaring tree [syn: Viburnum, genus Viburnum]