Webster's Revised Unabridged Dictionary · 1913

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.