This is the 7867th most frequent Polish word.
mikołajczyk
"Mikołajczyk" is a Polish surname derived from "Mikołaj," meaning "Nicholas."
Here, 'Mikołajczyk' is likely referring again to Stanisław Mikołajczyk, being used symbolically as an important figure in posters.
Mikołajczyk na plakacie był przedstawiony jako symbol narodowy.
Mikołajczyk on the poster was presented as a national symbol.
In this sentence, 'Mikołajczyk' is used as a proper noun, possibly a surname of a person.
Czy znasz jakiegoś Mikołajczyka, który mieszka w tej okolicy?
Do you know any Mikołajczyk who lives in this area?
Here, 'Mikołajczyk' is used as a proper noun referring to a historical figure, Stanisław Mikołajczyk.