This is the 12795th most frequent Polish word.
nieśmiertelność
Immortality.
In this case, 'nieśmiertelność' refers to the concept of immortality as a subject of discussion or storytelling.
Nieśmiertelność jest tematem wielu książek fantasy.
Immortality is a topic of many fantasy books.
Here, 'nieśmiertelność' is used to describe a state or condition that people aspire to achieve.
Ludzie od wieków marzyli o nieśmiertelności.
People have dreamt of immortality for centuries.
In this sentence, 'nieśmiertelność' refers to the characteristic of not being mortal, specifically pertaining to divine beings.