Definitions for ulmaceae
Ulmaceae, family Ulmaceae, elm family(noun)
a dicot family of the order Urticales including: genera Ulmus, Celtis, Planera, Trema
U.S. National Library of Medicine
A plant family of the order Urticales, subclass Hamamelidae, class Magnoliopsida. Members are trees and shrubs of temperate regions that have watery sap and alternate leaves which are lopsided at the base. The flowers lack petals.