steadfast
US /ˈsted.fæst/
UK /ˈsted.fæst/

1.
inébranlable, ferme, fidèle
resolutely or dutifully firm and unwavering
:
•
He remained steadfast in his loyalty to the company.
Il est resté inébranlable dans sa loyauté envers l'entreprise.
•
Her steadfast determination helped her overcome many obstacles.
Sa détermination inébranlable l'a aidée à surmonter de nombreux obstacles.