Noun | 1. | ![]() gum tree, gum - any of various trees of the genera Eucalyptus or Liquidambar or Nyssa that are sources of gum genus Nyssa, Nyssa - tupelos: deciduous trees of moist habitats especially swamps and beside ponds Nyssa aquatica, water gum - columnar swamp tree of southeastern to midwestern North America yielding pale soft easily worked wood black gum, Nyssa sylvatica, pepperidge, sour gum - columnar tree of eastern North America having horizontal limbs and small leaves that emerge late in spring and have brilliant color in early fall tupelo - pale soft wood of a tupelo tree especially the water gum |