Likewise or similarly in other lexica (references at Photius omicron45 Theodoridis), including Apollonius' Homeric Lexicon, and cf. also a scholion on Homer, Iliad 5.401 (where the neuter plural occurs). The present headword itself is apparently quoted from a context where it is feminine -- probably Homer, Iliad 11.846-7 (of a root, feminine accusative singular).
The scholiast perhaps thinks that the second element of the compound is related to fai/nw "I reveal"; LSJ connect it rather with qei/nw "I kill".
cf. omicron 56, omicron 57.