σμυγερός
From LSJ
ὕπνος δεινὸν ἀνθρώποις κακόν → sleep is a terrible evil for humans (Menander, Sententiae monostichoi 1.523)
English (LSJ)
ή, όν, poet. for μογερός,
A with pain, painful, A.R.4.1065: Comp., Id.2.374: Adv., Id.4.380; σμυγερὸν σμυγερῶς S.Ph.166 (anap.), as Brunck for στυγερὸν στυγερῶς; cf. Sch.ad loc., Hsch., Eust.1463.44:—Hom. has only the compd. Adv. ἐπισμυγερῶς (q.v.).
German (Pape)
[Seite 911] adv. σμυγερῶς, poet. statt μογερός, μογερῶς; Ap. Rh. 2, 374, u. adv., 4, 380, u. Sp., Hom. kennt nur das zusammengesetzte adv. ἐπισμυγερῶς, w. m. s.