Posted in Web Orangutan | Definition of Orangutan by Merriam-Webster July 12, 2019 Orangutan definition is – a largely herbivorous arboreal anthropoid ape (Pongo pygmaeus) of Borneo and Sumatra that is about 2/3 as large as the gorilla and has brown skin, long sparse reddish-brown hair, and very long arms. : https://www.merriam-webster.com/dictionary/orangutan