This is the 596th most frequent Catalan word.
greus
Serious; severe.
Here, "greus" is used as an adjective meaning "serious" or "severe," indicating the gravity of the athlete's injuries.
Les lesions que va patir l'atleta són molt greus.
The injuries that the athlete suffered are very serious.
In this case, "greus" as an adjective implies that the measures are important or significant in their nature and impact.
Han pres mesures greus contra la contaminació.
They have taken serious measures against pollution.
Here, "greus" also functions as an adjective, used to describe agreements with serious or significant implications.