The headword, which is the nominative singular masculine form of the adjective, may be a generic lexical reference or it may be extracted from a literary source, for which there are many possibilities. The presence of a similar gloss in the scholia to Nicander (see n. 1) might be seen as giving that source an edge over others.
For a gloss on the same word in a different sense see sigma 1189; and for a related word see sigma 1191.
[1] cf. the scholia to Nicander, Alexipharmaca 442 (nominative); Hesychius sigma1977 (accusative).
[2] Aristophanes, Frogs 878, with comments from the scholia thereto. Here the headword adjective appears in the dative plural neuter.