Fourth Definition

Further attempting to define piety, Euthyphro suggests it involves caring for the gods' well-being or interests.

Socrates questions the nature of this care, highlighting its ambiguity and the difficulty in defining it in practical terms, akin to the care one might provide a pet or master.

It can't be the sort of care a dog owner gives to its dog since that aims at improving the dog. But we can't improve the gods. If it's like the care an enslaved person gives his enslaver, it must aim at some definite shared goal. But Euthyphro can't say what that goal is.