This is the 1137th most frequent Polish word.
rokiem
"Rokiem" means "year" in instrumental case in Polish.
The word 'roku' is used in the genitive case to express duration ('over a year').
Mieszkam tu już od ponad roku.
I have been living here for over a year.
The word 'rokiem' is used in the instrumental case to show a specific point of reference ('the year of starting').
Rokiem rozpoczęcia nauki był 1995.
The year of starting school was 1995.
The word 'rokiem' is used in the instrumental case to relate to a specific year ('connected with the year').