Source : Webster's Revised Unabridged Dictionary (1913)

Olibanum \O*lib"a*num\, n. [LL., fr. Ar. al-luban frankincense;
   cf.Gr. ?, ?, of Semitic origin.]
   The fragrant gum resin of various species of {Boswellia};
   Oriental frankincense.

Source : WordNet®

olibanum
     n : an aromatic gum resin obtained from various Arabian or East
         African trees; formerly valued for worship and for
         embalming and fumigation [syn: {frankincense}, {gum
         olibanum}, {thus}]