- check something in
- check something in†1. to record that someone has returned something. •
I asked the librarian to check the book in for me.
•Did the librarian check in the book?
2. to take something to a place, return it, and make sure that its return has been recorded. •I checked the book in on time.
•Did you really check in the book on time?
3. to examine a shipment or an order received and make certain that everything ordered was received. •I checked the order in and sent a report to the manager.
•Tim checked in the order from the supplier to make sure that everything was there.
Dictionary of American idioms. 2013.