The name of Mt. Apo comes from Apo, a title of respect meaning revered elder in various languages of the surrounding Lumad tribes. It is the shortened form of the original Manobo and Kalagan name Apo Sandawa, the name of the spirit of the mountain. Apo Sandawa is also regarded as an ancestor spirit by the various Manobo and Kalagan tribes living in the foothills, including the Obo, Klata, Tagabawa, Matigsalug, Ata, Arumanen, Tinananen, Kulamanen, Tagakaulo, and Kagan peoples. The mountain itself is considered sacred grounds. Various rituals to Apo Sandawa are conducted by the supreme waylan (shaman) known as the diwata, who also serves as the medium for Apo Sandawa and the ancestor spirits of the Manobo and Kalagan tribes.