Collect dust

“Collect(ing) dust” is an idiomatic expression that means “not being used” or “sitting idle for a long time.” The idiom comes from the image of something standing unused in a room for a long time: eventually, the item will be covered in dust (if it’s not picked up, used, or cleaned).

Example: “Many people bought Peloton exercise bikes during the pandemic. But now, many of those bikes are just collecting dust.”

This means that those bikes are not being used. Although people bought those bikes, and have them in their homes, they are not using them. So because those bikes are sitting idle for an extended time, we say they are “collecting dust.”

More examples:

• The antique furniture in the attic has been collecting dust for generations.
• The kids were excited for their new toys at Christmas. But now it’s March and those toys are just collecting dust.
• I have a drawer full of chargers to old electronic devices. They’re just collecting dust, but I’m afraid to get rid of them.