refractarius
From LSJ
Ἐς δὲ τὰ ἔσχατα νουσήματα αἱ ἔσχαται θεραπεῖαι ἐς ἀκριβείην, κράτισται → For extreme diseases, extreme methods of cure, as to restriction, are most suitable.
Latin > English (Lewis & Short)
rē̆fractārĭus: a, um, adj. refringo,
I stubborn, obstinate, refractory: contumaces ac refractarios, Sen. Ep. 73, 1.
Latin > French (Gaffiot 2016)
rĕfrāctārĭus,¹⁶ a, um (refringo), casseur d’assiettes, querelleur : Sen. Ep. 73, 1.
Latin > German (Georges)
refrāctārius, a, um (refragor), widerhaarig, halsstarrig, ungeschmeidig, Sen. ep. 73, 1.