Orangutan comes from Malay orang hutan, meaning 'person of the forest' — though the Malay term may have originally referred to forest-dwelling humans, not apes.
A large, reddish-brown arboreal ape native to the rainforests of Borneo and Sumatra.
From Malay orang hutan, literally 'person of the forest,' from orang (person, human being) and hutan (forest, jungle). The name reflects the Malay recognition of the ape's human-like qualities. Interestingly, in Malay the term orang hutan originally referred to forest-dwelling human tribes, and applying it to the ape may have been a European misunderstanding or adaptation. Key
In Malay, orang hutan originally referred to indigenous forest-dwelling peoples, not apes. European naturalists may have borrowed the wrong referent when they applied the term to the great ape — essentially naming the animal 'forest person' based on a misunderstanding of who the Malays were actually talking about.