coriace

tough, leathery; tough, rugged

“Le turf, l'arène, on a grandi avec les jeux / Gladiateur courageux, mais la vie est coriace, on lutte comme on peut” — The turf, the arena, we grew up with the games / Courageous gladiator, but life is tough, we fight as best we can

Borrowed from Late Latin coriāceus (“leathery”), a derivative of corium (→ French cuir (“leather”)). Doublet of cuirasse.