noun (n)

• an aromatic gum resin obtained from various Arabian or East African trees; formerly valued for worship and for embalming and fumigation(noun.substance)

  Synonym:
  gum olibanum, olibanum, thus
  

  source: wordnet30
• A fragrant, aromatic resin, or gum resin, burned as an incense in religious rites or for medicinal fumigation. The best kinds now come from East Indian trees, of the genus Boswellia; a commoner sort, from the Norway spruce (Abies excelsa) and other coniferous trees. The frankincense of the ancient Jews is still unidentified.(noun)

  source: webster1913