perdifficiliter
From LSJ
σιγᾶν ἄμεινον ἢ λαλεῖν ἃ μὴ πρέπει → it's better to keep silence than to say what's not appropriate (Menander)
Latin > English (Lewis & Short)
perdiffĭcĭlĭter: adv., v. perdifficilis.
Latin > French (Gaffiot 2016)
perdiffĭcĭlĭtĕr (perdifficilis), très difficilement : Cic. Ac. 2, 47.
Latin > German (Georges)
perdifficiliter, Adv. (perdifficilis), sehr schwer, Cic. Acad. 2, 47.