serious, severe
Tendría que tener un desorden grave.
He would have to have a serious disorder.
— Algunos hombres buenos (1992)
Ya, ya, no exageres, tampoco fue tan grave lo que pasó.
Yeah, yeah, don't exaggerate, what happened wasn't that serious.
Tom está enfermo, pero no es grave.
Tom is sick, but it’s not serious.
En cualquier caso, fuera lo que fuera, no pudo haber sido grave.
In any case, whatever it was, it couldn't have been serious.
— Cónclave (2024)
It could be a serious problem.