From Iliad 5.405-409. Autenrieth gives παππάζω as ‘say papa, call one father.’ It is – threatening context aside – the cuddliest of the Homeric hapax legomena.

But the grey-eyed goddess Athena sets this one [Diomedes] upon you: the fool, nor does the son of Tydeus know this in his heart that not at all long-lived is he who fights with immortals, nor ever do his children at his knees call him papa when he has come home from war and dread strife.