lost property; something left behind
Refers to an item that was dropped or forgotten by its owner and is now lost.
I picked up my wallet at the station's lost-and-found office.
Please check if any lost property has been turned in.
dropping something; losing something
Refers to the act of dropping or losing an item, often without realizing it at the time.
I didn't realize I had dropped something.
People who often lose things need to be careful.
I handed the lost item in to the station staff.
I ended up losing something on the train.
There was someone searching for a lost item in the park.
His lost item was found at the police box.