The unglossed headword phrase, in the nominative or accusative, is presumably quoted from somewhere. For its (neuter) noun cf. generally phi 720, phi 721; however, it seems to be cited here for the form (attested only here) of its adjective, apparently a late alternative spelling of nh/pios, -a, -on, "not yet speaking, infantile, stupid"; see LSJ s.v.
The neuter noun fro/nhma can be used either neutrally ("mind, thought") or in an adverse value-judgment( "pride, arrogance"); see LSJ s.v. and a similar expression at alpha 4312. An analogous entry appears at ps.-Zonaras 1398.19: *nhpei/a kai\ nhpie/h. h( a)frosu/nh, nêpeia and nêpieê: "folly".
[1] For the gloss Adler also cites the unpublished Ambrosian Lexicon (228). [In her critical apparatus Adler notes that mss AF omit this entry, though a user of A (Parisinus 2626) added it in the margin; ms V placed it after entry nu 324; and ms M inserted a cross-reference to kaino/n, "fresh", kappa 1171.]