This is the 423rd most frequent Polish word.
członków
"Members" (genitive plural form of "członek").
In this sentence, 'członków' is the genitive plural form of 'członek,' meaning 'members,' indicating possession—belonging to the members of the club.
Dyskusja członków klubu była niezwykle interesująca.
The discussion of the club members was extremely interesting.
Here, 'członków' appears as part of the phrase 'jednego członków,' which commonly denotes a genitive plural context instrumental for indicating association with a subset of a group.
Rodzina wsparła jednego członków lokalnej społeczności.
The family supported one member of the local community.
In this use, 'członków' is in the genitive plural form, used with numerals and specific phrases to denote quantity or association.