The Collaborative International Dictionary of English v.0.48:

Incense \In"cense\, n. [OE. encens, F. encens, L. incensum, fr.
   incensus, p. p. of incendere to burn. See Incense to
   inflame.]
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   1. The perfume or odors exhaled from spices and gums when
      burned in celebrating religious rites or as an offering to
      some deity.
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            A thick cloud of incense went up.     --Ezek. viii.
                                                  11.
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   2. The materials used for the purpose of producing a perfume
      when burned, as fragrant gums, spices, frankincense, etc.
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            Nadab and Abihu, the sons of Aaron, took either of
            them his censer, and put fire therein, and put
            incense thereon.                      --Lev. x. 1.
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   3. Also used figuratively.
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            Or heap the shrine of luxury and pride,
            With incense kindled at the Muse's flame. --Gray.
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   Incense tree, the name of several balsamic trees of the
      genus Bursera (or Icica) mostly tropical American. The
      gum resin is used for incense. In Jamaica the
      Chrysobalanus Icaco, a tree related to the plums, is
      called incense tree.

   Incense wood, the fragrant wood of the tropical American
      tree Bursera heptaphylla.
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WordNet (r) 3.0 (2006):

incense tree
    n 1: any of various tropical trees of the family Burseraceae
         yielding fragrant gums or resins that are burned as incense