sideris
Ἐς δὲ τὰ ἔσχατα νουσήματα αἱ ἔσχαται θεραπεῖαι ἐς ἀκριβείην, κράτισται -> For extreme diseases, extreme methods of cure, as to restriction, are most suitable.
Corpus Hippocraticum, Aphorisms 1.6.2Latin > French (Gaffiot)
(1) sīdĕris, gén. de sidus.