Nyssaceae nys·sa·ceae uncommon noun 1. a family of dicotyledonous trees of order Myrtales that includes the sour gum trees Synonymsfamily Nyssaceaesour-gum familytupelo family Related words Broader terms dicot family Parts Myrtales Part of Nyssa WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.
