Aṣṭādhyāyī
The Aṣṭādhyāyī (/ˌæstədˈjɑː(j)i/; Sanskrit: अष्टाध्यायी [ɐʂʈaːdʱjáːjiː]) is a grammar text that describes a form of the Sanskrit language.
Authored by the ancient Sanskrit scholar Pāṇini and dated to around 6th c. bce, 6-5th c.BCE and 4th c.BCE, it describes the language as current in his time, specifically the dialect and register of an élite of model speakers, referred to by Pāṇini himself as śiṣṭa. The work also accounts both for some features specific to the older Vedic form of the language, as well as certain dialectal features current in the author's time.
The Aṣṭādhyāyī employs a derivational system to describe the language.
The Aṣṭādhyāyī is supplemented by three ancillary texts: Akṣarasamāmnāya, Dhātupāṭha and Gaṇapāṭha.