What is another word for underground room?
Pronunciation: [ˌʌndəɡɹˈa͡ʊnd ɹˈuːm] (IPA) 
An underground room can be referred to by many synonyms, depending on its purpose and location. Some common synonyms for an underground room include cellar, basement, bunker, vault, crypt, catacomb, hideaway, and subterranean chamber. A cellar typically refers to a room used for storage, often with food, wine, or other supplies. A bunker typically denotes a room built for safety or protection, such as a bomb shelter. A vault is often associated with banks or jewelry stores and is used to store valuables securely. A crypt and catacomb are often associated with burial places. A hideaway can refer to a secret or secluded spot, while a subterranean chamber can refer to any underground room or space.
