This is the 179th most frequent Serbian word.
првом
The word "првом" in Serbian means "the first" in the instrumental case (e.g., "with the first" or "by the first").
In this sentence, 'првом' is the dative or locative singular masculine form of the ordinal number 'први' (first), used here to describe a city where someone stopped.
Када сам путовао у Београд, свратио сам у првом граду на путу.
When I traveled to Belgrade, I stopped in the first city on the way.
Here, 'првом' represents the locative singular masculine/neuter form of the ordinal number 'први', describing the specific quarter of the year.
У првом тромесечју ове године приметили смо велики повећај приходе.
In the first quarter of this year, we noticed a significant increase in revenue.
In this context, 'првом' is the locative singular masculine form of 'први', indicating a specific day being referenced.