The substantive part of the unglossed headword phrase is an adjective in masculine/feminine nominative singular form; the addition of the definite article shows that it depends here on a feminine name or noun.
An ascription for the entry is unclear, and Adler nothing says about it. Amongst the common sources of the Suda the likeliest connection with a grammatical feminine (this lemma occurs in the Synagoge and Hesychius in masculine dependence) is Laurentianus 59.16 at folium 173v: gamh/lios w)dh/ 'bridal song', which seems to refer to the scholia to Homer, Iliad 18.498. So it could be an Ambrosian entry, but this should be corroborated by an examination of the manuscripts Ambrosianus B12 sup. and Atheniensis 1065. Meanwhile, other possibilities for the feminine noun are 'bed' (eu)nh/, koi/th) and 'feast/sacrifice' (qusi/a); see LSJ s.v.