svršavati

1. dated to finish; to complete
   Upravo svršavam posao, pa dolazim. — I'm just finishing up work, then I'll come.
   Svake večeri svršava zadatke pre devet. — Every evening he finishes his assignments before nine.
2. colloq. vulg. (sexual) to come; to cum
   Rekla je da on uvek prebrzo svršava. — She said he always comes too quickly.

The sense 'to finish' is dated in contemporary Serbian and is found mainly in older speakers' usage and older texts (the examples for sense 1 reflect that usage); the neutral word today is završavati, since svršavati is usually understood in the sexual sense.