A pandanus language is an elaborate avoidance language among several of the peoples of the eastern New Guinea Highlands, used when collecting pandanus nuts.
Annually, people camp in the forest to harvest and cook the nuts of Pandanus brosimus. Many normal words are thought to be unhealthy for the plants, as they carry associations inimical to the proper growth of the nuts. An elaborate vocabulary of up to a thousand words and phrases has developed to replace the taboo vocabulary. They may also be motivated by the fact that the harvest takes place in deep forest thought to be inhabited by nature spirits that make the area dangerous to human activity. Pandanus language should never be used outside the area where the trees grow.
Pandanus registers have been best documented for Kewa and Kalam. See Kewa for an illustration.