obrnuti

1. to turn; to turn over
   Obrni ključ dva puta i vrata će se otvoriti. — Turn the key twice and the door will open.
   Obrnuo je list i nastavio da čita. — He turned the page and kept reading.
2. (of order, roles) to reverse; to invert
   Hajde da obrnemo redosled i počnemo od kraja. — Let's reverse the order and start from the end.
   Sada su se uloge obrnule. — Now the roles have been reversed.
3. (obrnuti se) to turn around
   Obrnula se kad je čula svoje ime. — She turned around when she heard her name.
4. colloq. (on the phone) to call, to phone; to dial
   Obrni me kad stigneš kući. — Call me when you get home.
   Obrnuo sam njegov broj, ali se nije javio. — I dialled his number, but he didn't answer.
5. (of money) to turn over; to put into circulation
   Brzo je obrnuo pare i udvostručio ulog. — He quickly turned the money over and doubled his stake.

For "to turn" and "to call", okrenuti is more common; the adverb obrnuto means "the other way round".