gum tree

from The Century Dictionary.

• noun See gum, 3.

from the GNU version of the Collaborative International Dictionary of English.

• noun The black gum (Nyssa multiflora), one of the largest trees of the Southern States, bearing a small blue fruit, the favorite food of the opossum. Most of the large trees become hollow.
• noun A tree of the genus Eucalyptus; a eucalypt. See eucalpytus
• noun The sweet gum tree of the United States (Liquidambar styraciflua), a large and beautiful tree with pointedly lobed leaves and woody burlike fruit. It exudes an aromatic terebinthine juice.
• noun The sour gum tree.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A eucalyptus tree.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun any of various trees of the genera Eucalyptus or Liquidambar or Nyssa that are sources of gum