This is the 8447th most frequent Polish word.
polakiem
"Polakiem" means "a Pole" (instrumental case, referring to a Polish person).
In this sentence, 'Polakiem' is the instrumental case of 'Polak', describing the speaker's nationality.
Ja jestem Polakiem.
I am a Polish person.
Here, 'polakiem' is the instrumental case of 'Polak', used to describe interacting with someone of Polish nationality.
Chciałbym porozmawiać z polakiem.
I would like to speak with a Polish man.
In this example, 'Polakiem' is used in the instrumental case to denote someone having become a person of Polish nationality.