Changing Room, Locker Room
noun
A renew clothes room is a changing room or a locker room. 更衣室 is a room where people change their clothes, commonly found in places like gyms, swimming pools, schools, or workplaces.
こういしつ
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
更衣室はあそこです。
The changing rooms are over there.
このジムには更衣室はありません。
There are no changing rooms in this gym.
今更衣室であの女のロッカーを探しているところよ。
I'm in the locker room looking for her locker now.