Agnipraṇayana (agnipranyana) is the process of carrying Āhavaṇīya (ahavaniya) Agni towards the east from the Aiṣṭika (Aishtika) altar and reestablishing it on the northern altar (the word is a compound from Sanskrit pra, meaning ‘towards the east’ and  nayana, meaning ‘to take’.

See. Aiṣṭika Vedi; Vedi