An antechamber is a smaller room

Room

A room is any distinguishable space within a structure.Room may also refer to:* Room , by Emma Donoghue* Room, Nepal* Room for PlayStation Portable, a social networking service* Thomas Gerald Room , Australian mathematician...

 or vestibule

Vestibule (architecture)

A vestibule is a lobby, entrance hall, or passage between the entrance and the interior of a building.The same term can apply to structures in modern or ancient roman architecture. In modern architecture vestibule typically refers to a small room or hall between an entrance and the interior of...

 serving as an entryway

Entryway

An entryway is a hall that is generally located at the front entrance of a house. An entryway often has a coat closet, and usually has linoleum or tile flooring rather than carpet, making it an easy-to-clean transition space between the outdoor and indoor areas...

 into a larger one. The word is formed of the Latin ante camera, meaning "room before".

In some cases, an antechamber provides a space for a host to prepare or conduct private business away from a larger party or congregation. In a theme park, an antechamber may be used to tell guests about a ride before they experience it.