"Unused space" refers to an area or room that is not being utilized or occupied effectively. It could be a physical area in a building or a virtual space in digital platforms. Full definition
For a start, it's possibly the largest bit of unused space in your home, yet often the simplest and least disruptive to convert. (idealhome.co.uk)
The company began in 2008 as an online platform matching budget travelers with people looking to make money from renting unused space in their homes. (realtormag.realtor.org)
You can shake the phone three times when in this mode to automatically line up your icons and eliminate unused space on the home screens. (recode.net)