(Ἀγαθοδαίμων or Ἀγαθὸς Δεὸς), the "Good God," a divinity in honour of whom the Greeks drank a cup of unmixed wine at the end of every repast. A temple dedicated to him was situated on the road from Megalopolis to Maenalus in Arcadia. Pausanias (8.36.3) conjectures that the name is a mere epithet of Zeus. (Comp. Lobeck, ad Phrynich. p. 603.)
[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