Definition of magnoliaceous in US English:

magnoliaceous

adjective

Botany
  • Belonging to or characteristic of the family Magnoliaceae of dicotyledonous plants (formerly taken to include the Winteraceae), of which Magnolia is the typical genus.

Origin

Mid 19th century; earliest use found in Thomasina Ross (fl. 1852). From magnolia [adjective] + -aceous, after scientific Latin Magnoliaceae (A. P. de Candolle Essai sur les Propriétés Médicales des Plantes (ed. 2, 1816) 72; earlier in French as magnoliacées, plural noun).