This is the 7400th most frequent Polish word.
klubu
"Klubu" is the genitive or locative singular form of "klub," meaning "club" in English.
'Klubu' here also uses the genitive case, commonly used in negative sentences negating the existence of the noun ('klub').
Nie ma klubu w naszej okolicy.
There is no club in our neighborhood.
Here, 'klubu' is the genitive case of 'klub' used to indicate motion towards a location when combined with the preposition 'do'. This specifies the direction of movement.
Idę do klubu wieczorem.
I am going to the club in the evening.
In this context, 'klubu' indicates possession (the 'members of the club') and is in the genitive case after 'członkowie', which means 'members' and defines belonging.