Clubroom
noun
A club room is a clubroom!
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
メディア部の部室には、たくさんのCDがあります。
There are many CDs in the media club room.
ここは野球部の部室ですか?ニオイで分かりますよ。
Is this the baseball club room? I can tell by the odor.
まずは部室でユニフォームに着替えて来て。
First, go get changed into a uniform in the clubroom.