kucnuti

1. (at a door, window) to knock
   Neko je kucnuo na vrata, idi otvori. — Someone knocked at the door, go and open it.
   Kucnuo sam dva puta, ali niko nije odgovorio. — I knocked twice, but nobody answered.
2. (with an object) to tap
   Kucnuo je olovkom o sto da ućutimo. — He tapped his pencil on the desk to make us be quiet.
3. formal (of a time, hour) to strike; to come
   Kucnuo je čas da se konačno odlučimo. — The hour has come for us to finally decide.
4. (kucnuti se, with glasses) to clink glasses
   Kucnuli smo se i nazdravili domaćinu. — We clinked glasses and toasted the host.
   Hajde da se kucnemo! — Let's clink glasses!

Used with na + acc. (kucnuti na vrata); the imperfective is kucati.