This is the 267th most frequent Polish word.
marcin
"Marcin" is a Polish given name, equivalent to "Martin" in English.
In this sentence, 'Marcin' is used as a proper noun referring to a person's name, specifically a male name.
Marcin jest moim najlepszym przyjacielem.
Marcin is my best friend.
Here, 'Marcin' is used as part of a proper noun designating a specific district's name.
Dzielnica, w której mieszka, nazywa się Święty Marcin.
The district where he lives is called Saint Marcin.
This instance uses 'Marcin' in its historical and cultural context, referring to the saint, a historically significant figure.