kompa

1. colloq. (about a friend, as address) buddy; mate; pal
   Hvala ti, kompa, dugujem ti jedno pivo. — Thanks, mate, I owe you a beer.
   Moj kompa već dve godine radi u Nemačkoj. — My buddy has been working in Germany for two years.

It declines like nouns in -a but takes masculine agreement: moj kompa.