return slot; coin return
Specifically the slot or opening where a vending machine returns coins or change.
Your change will come out of the return slot.
tray return station
Used in cafeterias or food courts for the designated area where customers return their trays after eating.
When you finish eating, please return your tray to the tray return station.
Compound of 返却 (return, give back) and 口 (opening, mouth).