immortaliter
From LSJ
ἐν ταῖς ἀνάγκαις χρημάτων κρείττων φίλος → it is better in times of need to have friends rather than money, a friend in need is a friend indeed (Menander, Sententiae monostichoi 143)
Latin > English (Lewis & Short)
immortālĭter: (inm-), adv., v. immortalis.
Latin > French (Gaffiot 2016)
immortālĭtĕr,¹⁶ éternellement : Aug. Conf. 4, 2 || [fig.] immortaliter gaudere Cic. Q. 3, 1, 9, éprouver une joie infinie.