Both headword and gloss are nominative masculine plurals. Probably from a scholion to Homer, Odyssey 7.307, where the rare headword occurs (web address 1). See also under omicron 251.
Though the glossing adjective as such is common in all periods, its superlative, as here, is rare until the C4 AD onwards; see e.g. Greek Anthology 5.3.3 (Antipater of Thessalonica).