rvati se

1. (rvati se s + instr.) to struggle; to grapple
   Već mesecima se rvem sa srpskom gramatikom. — I've been struggling with Serbian grammar for months.
2. (rvati se, in sport) to wrestle
   Dečaci su se rvali u travi. — The boys were wrestling in the grass.

Used with se: rvati se s kim/čim; the sport is rvanje.