γηρόβοσκος
From LSJ
Μέμνησο νέος ὤν, ὡς γέρων ἔσῃ ποτέ → Iuvenis memento te fore aliquando senem → Bedenke jung schon, dass dereinst ein Greis du bist
English (Woodhouse)
(see also: γηροτρόφος) cherishing in old age, cherishing parents in old age, tending in old age