n. An aromatic gum resin yielded by trees of the genus Boswellia, much used from ancient times, especially for burning as incense in religious observances. See olibanum. Also called gum thus.n. Hence2, Some other resin resembling olibanum in any way.n. The principal trees yielding resinous exudations known as frankincense are: Boswellia Carterii (see Boswellia)n. the Norway spruce, Abies Picea;n. the loblolly-pine, Pinus Tæda (see frankincense, 2); andn. Styrax punctata (see Styrax).