in
to leave bags or cases with an official to be put on a plane or train :
We checked in our luggage and went through to the departure lounge.
—related noun check-in
in
to leave bags or cases with an official to be put on a plane or train :
We checked in our luggage and went through to the departure lounge.
—related noun check-in
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005