From WordNet (r) 3.0 (2006) [wn]:
macadamia
n 1: any tree of the genus Macadamia [syn: macadamia,
macadamia tree]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
macadamia \macadamia\ n.
1. any tree of the genus Macadamia, especially {Macadamia
ternifolia}.
Syn: macadamia tree.
[WordNet 1.5]
2. A macadamia nut.
[PJC]