Question

check
  in

Accepted Answer

1 to
  arrive (at a hotel) and sign the register: We checked in last night 2 to book
  a room (for someone at a hotel). He checked us in at the Mandarin Hotel. 3 to
  hand in (eg one's baggage at an airport terminal): We'll check in our
  luggage, and go and have a meal.

Check Checked In Arrive Hotel Sign Register Night