Sometimes classified as a superorder

• A group of families or trees and shrubs and herbs having well-developed perianths and apocarpous ovaries and generally regarded as the most primitive extant flowering plants
• Contains 36 families including Magnoliaceae and Ranunculaceae

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Dicotyledonae \Dicotyledonae\ n. (Bot.) a class of plants comprising those seed plants that produce an embryo with two cotyledons and net-veined leaves; divided into six (not always well distinguished) subclasses (or superorders): Magnoliidae and Hamamelidae ...

Wikipedia Word definitions in Wikipedia
Magnoliidae is a botanical subclass name; it may refer to: Magnoliids , a major group of basal angiosperms. Magnoliidae sensu Chase & Reveal , a botanical subclass consisting of all angiosperms. In the Dahlgren and Thorne systems, a group consisting of ...