The phrase "broom closet" refers to a small, usually narrow space, similar to a cupboard or storage room, where brooms and cleaning supplies are stored. Full definition
One New York Times article reported on workers huddled in broom closets for a quiet chat. (inc.com)
The first Papa Johns» pizza was baked in the renovated broom closet of a bar. (entrepreneur.com)
Have your laundry room double as storage space for other items; for instance, create a vertical broom closet for household cleaning supplies. (styleathome.com)