Nikāya is a Pāḷi word meaning "volume." It is used like the Sanskrit word āgama "basket" to mean "collection," "assemblage," "class" or "group" in both Pāḷi and Sanskrit. It is most commonly used in reference to the Buddhist texts of the Sutta Piṭaka but can also refer to the monastic divisions of Theravāda Buddhism.
In addition, the term Nikāya is sometimes used in contemporary scholarship to refer to early Buddhist schools.