A locker is a small cupboard or storage space that can be locked, usually used in schools or gyms to store personal belongings like books, clothes or bags. Full definition
I feel like I spent most of my life in locker rooms and hot school buses that went through the hood. (sbnation.com)
I have seen it used a lot in locker rooms, kitchens, and bathrooms. (biggerpockets.com)
Here was a manager that had the support of locker room with maybe the biggest collective ego (and that is saying something in modern football). (laligablog.com)