The headword, a masculine noun in the nominative singular, is a rare byform of the feminine noun stonaxh/. This form is attested elsewhere only at Etymologicum Magnum 100.35 (post-Suda) and is probably a generic lexical reference.
The gloss is a more commonplace masculine noun; cf. under mu 1372, sigma 1142, omicroniota 98. Its deployment here finds a close parallel in the D scholia to Homer, Iliad 2.39, where feminine accusative plural stonaxa/s is glossed with stenagmou/s; cf. Hesychius sigma1921, Synagoge sigma237, Photius sigma587 Theodoridis. For a related word see sigma 1142.