ˈcheck-in BrE AmE noun
1 . [singular] a place where you report your arrival at an airport, hotel, hospital etc:
the check-in desk
Make sure you’re at the check-in by 5.30.
2 . [uncountable] the process of reporting your arrival at an airport, hotel, hospital etc:
Ask your travel agent about check-in times.
⇨ check in at ↑ check 1