immutabiliter
From LSJ
οὐ δικαίως θάνατον ἔχθουσιν βροτοί, ὅσπερ μέγιστον ῥῦμα τῶν πολλῶν κακῶν → unjustly men hate death, which is the greatest defence against their many ills | men are not right in hating death, which is the greatest succour from our many ills
Latin > English (Lewis & Short)
immūtābĭlĭter: adv., v. 1. immutabilis.
Latin > French (Gaffiot 2016)
immūtābĭlĭtĕr, d’une façon immuable : Dig. 45, 1, 99, 1.