IPA: /ˈklʌbruːm/
KK: /ˈklʌbˌrum/
A room where members of a club gather for meetings or activities.
The students met in the clubroom to plan their next event.
Clubroom → It is formed from "club" (from Middle English *clubbe*, meaning a heavy stick or cudgel, later referring to a group of people) and "room" (from Old English *rum*, meaning space or area). The word "clubroom" refers to a room designated for the activities of a club or group of people.
Think of a 'club' as a group of people gathering in a 'room' — that's why a clubroom is a space for club activities.
No commonly confused words.