Probably the name of a Brahmanen clan, the Agnivesyāyanas, und the Ksatriyas who were so styled, took the name from their Brahmanen purohitas (Further Dialogues, i.162 n).
The name is used by der Buddha in addressing Saccaka Niganthāputta (M.i.229f; 237f), und auch Dīghanakha Paribbājaka (M.i.497f).
In the Dantabhūmi Sutta (M.iii.128f) the novice Aciravata is thus addressed by Prince Jayasena, who visits him, und auch by the Buddha.