δύστρωτος
From LSJ
ἀγεωμέτρητος μηδεὶς εἰσίτω → no one ignorant of geometry may enter, let no one ignorant of geometry enter, let no one ignorant of geometry come in
English (LSJ)
ον,
A hard to injure, σιδήρῳ καὶ λίθῳ Plu.2.983d, cf. Apollod.Poliorc. 139.8: Comp., Gal.UP1.2.
German (Pape)
[Seite 689] schwer zu verwunden, Plut. sol. anim. 35.