Guelderrose\'Guel"der*rose'\, n. [Supposed to be brought from Guelderland; hence, D. Geldersche roos, G. Gelderische rose, F. rose de Gueldre, It. rose di Gueldra, Sp. rosa de Gueldres.] (Bot.) A cultivated variety of a species of Viburnum (V. Opulus), bearing large bunches of white flowers; -- called also snowball tree.