Both the primary and the secondary headwords here are in the accusative case. They appear as such, together, in Theodoret's Quaestiones in Octateuchum 142.10-12, itself prompted by the occurrence of u(podu/thn in Exodus 28.31 (and 36.29) LXX. See also Moeris, Lexicon atticum s.v. xitwni/skos.
[1] Likewise or similarly in other lexica; references at Photius upsilon198 Theodoridis.
[2] epsilon 2055; cf. ps.-Zonaras (where the opposite meaning is given, obviously by mistake) and Pollux 7.45, where Sophocles fr. 439 Radt, Thespis fr. 1 Snell, and Nicochares fr. 5 Kock (now 8 K.-A.) are quoted. In the present context, however, e)pendu/thn is likely to be quoted from John 21.7.