This is the 8359th most frequent Polish word.
piast
A "piast" refers to a member of the first ruling dynasty of Poland or a caretaker/guardian in historical context.
In this sentence, 'Piast' is used as a proper noun referring to a historical figure who is foundational to a royal Polish dynasty.
Piast był legendarnym protoplastą dynastii piastowskiej.
Piast was the legendary founder of the Piast dynasty.
Here, 'piast' is used figuratively to refer to someone who oversees and takes care of familial matters.
Jako piast grona rodzinnego, zawsze dbam o dobro moich bliskich.
As the steward of the family circle, I always care for the well-being of my relatives.
In this context, 'Piasts' refers to the members of the historical Piast dynasty, illustrating the term's usage in a plural form.