blue gum

noun2

1. •
   Any of various eucalyptus trees having blueish leaves, especially Eucalyptus globulus.

   • Now there are five, solidly built, with concrete bases, galvanized poles and struts, and heavy-gauge mesh, shaded by young bluegum trees. — 1999
2. •
   (slang, offensive) A person of sub-Saharan African origin.