This headword as such is used of several male deities (e.g. Ares and Apollo: see LSJ s.v.) and also of female ones, as required here: Eris (Homer, Iliad 20.48) and Athena (Homer, Iliad 13.128, Odyssey 22.210). Thus this whole entry, epithet plus gloss, comes from the scholiastic and lexicographical tradition; cf. Apion fr.66; Apollonius, Homeric Lexicon 107.3; Photius lambda88 Theodoridis with other references.
The etymology of the gloss is repeated at the end of sigma 781 and sigma 788; note, however, that LSJ s.v. derives it, rather, from the verb seu/w (and so translates the epithet people-stirring or people-rousing).