Both headword and "gloss" are varieties of the aorist active infinitive of the verb sto/rnumi (cf. sigma 1146). The former is used several times in Homer (see n. 1) and is in fact the standard form of the infinitive in Classical Greek and earlier; the "gloss" is a late-Greek development.
[1] = Synagoge sigma240, Photius sigma590 Theodoridis; cf. Hesychius sigma1931. Probably from commentary to Homer; cf. scholia to Iliad 9.621 (singled out by Latte and Theodoridis), Odyssey 4.298.