Definition: name of a great grammarian who is believed to have written an exhaustive treatise on grammar before Pāṇini; cf. the famous verse of Bopadeva at the commencement of his Dhātupāṭha इन्द्रश्चन्द्र: काशकृत्स्नापिशली शाकटायनः । पाणिन्यमरजैनेन्द्रा जयन्त्यष्टादिशाब्दिका: ॥ No work of Indra is available at present. He is nowhere quoted by Pāṇini. Many quotations believed to have been taken from his work are found scattered in grammar works, from which it appears that there was an ancient system prevalent in the eastern part of India at the time of Pāṇini which could be named ऐन्द्रव्याकरणपद्धति, to which Pāṇini possibly refers by the word प्राचाम्. From references,it appears that the grammar was of the type of प्रक्रिया, discussing various topics of grammar such as alphabet, coalescence, declension, context, compounds, derivatives from nouns and roots, conjugation, and changes in the base. The treatment was later on followed by Śākaṭāyana and writers of the Kātantra school.For details see Mahābhāṣya ed. by D. E. Society, Poona, Vol. VII pages 124-127.