The headword -- apparently from the same root as o)/yomai, o)/pwpa (omicron 479) -- is used of divine vengeance and (less often) divine favor; also of human respect for the gods. By folk etymology it was connected with o)/pisqen, as the gloss here suggests (literally "turning about").
Similar glosses in ps.-Herodian, the Ambrosian Lexicon (according to Adler), ps.-Zonaras, a scholion on Homer, Iliad 16.388 (see web address 1), and Hesychius s.vv. o)/pida (omicron999) and o)/pin (omicron1005).