As a deity name
Name 502 of the Hanuman Sahasranāma — Rasvin Samhita / Brahmanda Purana, as taught by Lord Ram / Sages
Name 967 of the Narasimha Sahasranāma — Brahmanda Purana / Narasimha Purana, as taught by Sages to Assembly of Devotees
As a Hindi name
No reading on this path — this spelling has no entry in our Hindi sources, and no near neighbour is attested there either. We say so rather than invent one.
As a Sanskrit word
Meaning
‘horse-necked’, N. of a form of Viṣṇu (manifested accord. to one legend, in order to recover the Veda carried off by two Daityas called Madhu and Kaiṭabha)
Scripturally attested Verified split — attested membersMultiple readings (5)Why this matches what you typed
M1 · same meaning "hayagrīvāya" is the dative of "hayagrīva" — the same word in a different grammatical case.
Dictionary citations
haya—grīva m. ‘horse-necked’, N. of a form of Viṣṇu (manifested accord. to one legend, in order to recover the Veda carried off by two Daityas called Madhu and Kaiṭabha), Pañcar.
of a Daitya (also called brahma-veda-prahartṛ, as having carried off the Vedas at the dissolution of the universe caused by Brahma's sleep at the end of the past Kalpa; in order to recover them, Viṣṇu became incarnate as a Matsya or fish, and slew Haya-grīva), Hariv.; Kathās. &c.
Alternative readings
More than one analysis survives full verification. That ambiguity is real, so we show every reading rather than pick one silently.
Caveats
Sources contain errors and engines have limits; every claim above carries its citation so you can verify it. This is guidance about names and their sources — not religious or astrological consultation. How we work · Our sources