The headword and the glosses are all in the accusative singular, the headword so common that establishing its source can only be guesswork. (Adler points to Homer, Iliad 14.433, on the basis of the scholia there, but there is no exact fit.)
As a whole the entry = Synagoge and Photius pi1102 Theodoridis, where however the third gloss, 'crossing of a river', is oddly in the nominative case. Compare also Etymologicum Magnum 683.10, where the headword and first gloss occur in the nominative plural; and pi 2083.