This is the 697th most frequent Serbian word.
професора
The Serbian word "професора" means "professor" (genitive or accusative singular, or nominative plural).
The word 'професором' here is in the instrumental case, used to indicate the person with whom the subject is performing the action.
Јуче сам разговарао са новим професором.
Yesterday, I talked with the new professor.
The word 'професора' here is in the accusative case, serving as the direct object of the action (being greeted by the students).
Професора су сви ученици поздравили по доласку.
All the students greeted the professor upon his arrival.
The word 'професора' here is in the genitive case, used to indicate possession or association (the books belonging to Professor Jovanović).