konkurencija

1. competition; rivalry
   Konkurencija na tržištu je sve jača. — Competition on the market is getting stronger.
   Za to mesto je velika konkurencija. — There's a lot of competition for that position.
2. the competition; rivals
   Konkurencija je spustila cene. — The competition lowered their prices.
   Prešao je da radi za konkurenciju. — He went to work for the competition.
3. (in sports) category; field
   Osvojila je zlato u ženskoj konkurenciji. — She won gold in the women's category.

In the sense "rivals" it is used in the singular as a collective noun.