WordNet (r) 3.0 (2006):

fever tree
    n 1: any of several trees having leaves or bark used to allay
         fever or thought to indicate regions free of fever
    2: ornamental shrub or small tree of swampy areas in
       southwestern United States having large pink or white sepals
       and yielding Georgia bark for treating fever [syn: fever
       tree, Georgia bark, bitter-bark, Pinckneya pubens]
    3: tall fast-growing timber tree with leaves containing a
       medicinal oil; young leaves are bluish [syn: blue gum,
       fever tree, Eucalyptus globulus]
    4: African tree supposed to mark healthful regions [syn: fever
       tree, Acacia xanthophloea]