(Ἐπόψιος), that is, the superintendent, occurs as a surname of several gods, such as Zeus (Apollon. 2.1124), Apollo (Hesych. sub voce comp. Soph. Philoct. 1040), and of Poseidon at Megalopolis. (Paus. 8.30.1.)
[L.S]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890