This is the 118th most frequent Polish word.
związku
"Związku" means "of the union" or "of the relationship" in English, depending on context.
Here, the word 'związku' refers to an organization or association, specifically a union.
Jestem członkiem tego związku od pięciu lat.
I have been a member of this union for five years.
In this context, 'w związku z' is a set phrase meaning 'in connection with' or 'due to'.
W związku z tym, postanowiliśmy podjąć nowe kroki.
In relation to this, we decided to take new steps.
Here, 'związku' refers to a personal or romantic relationship.