ἐπιδερμίς
From LSJ
κάλλιστον ἐφόδιον τῷ γήρᾳ ἡ παιδεία (Aristotle, quoted by Diogenes Laertius 5.21) → the finest provision for old age is education
English (LSJ)
ίδος, ἡ, A outer skin, epidermis, Hp.Nat.Puer.20, etc. II. web of water-birds' feet, Arist. ap. Sch.Il.2.460.
German (Pape)
[Seite 936] ίδος, ἡ, die Oberhaut, Hippocr. u. Sp.; Schwimmhaut der Wasservögel, Schol. Il. 2, 460.