Source : Webster's Revised Unabridged Dictionary (1913)

Neem tree \Neem" tree`\ [Hind. n[=i]m.] (Bot.)
   An Asiatic name for {Melia Azadirachta}, and {M. Azedarach}.
   See {Margosa}.

Source : WordNet®

neem tree
     n : large semi-evergreen tree of the East Indies; trunk exudes a
         tenacious gum; bitter bark used as a tonic; seeds yield
         an aromatic oil; sometimes placed in genus Melia [syn: {neem},
          {nim tree}, {margosa}, {arishth}, {Azadirachta indica},
         {Melia Azadirachta}]