A checkroom is a room in a restaurant, theatre, museum, or hall where you leave your coat, bag, or umbrella, and someone watches it until you come back. You usually get a little ticket. This is mainly American; British people more often say cloakroom, and for bags at a station, left luggage. The check here means leave this with me — the same as checking a coat — not look for mistakes. It is a public-place word, a little old-fashioned: you will see it on signs more than you will hear it in young people's chat. In Taiwan the same job is usually a 寄物處.