A "red room" in a nightclub can refer to different things depending on the context. Here are some possible meanings:

• A smaller and more intimate room: According to a TripAdvisor review, a nightclub may have a "Red Room" that is smaller and more intimate than the main bar room. This is not a universal definition, but rather a specific example of how a nightclub might use the term.

• A hidden room for BDSM activities: According to an Urban Dictionary definition, a "Red Room" can be a room with red walls where people engage in BDSM activities such as tying each other up and using whips, chains, and ball gags. This definition is not specific to nightclubs and may refer to any private space where such activities take place.

• A dive bar in Long Beach, California: There is a dive bar called "Red Room" in Long Beach, California, according to Yelp. This is an example of a nightclub or bar that uses "Red Room" as its name.

• An urban legend about a dark web site: According to RationalWiki, a "red room" is an urban legend about a hidden website or service on the "dark web" where people can watch or participate in live torture and murder. However, the article notes that it is near-impossible to stream live video over the Tor network or other anonymity networks, so such a service is unlikely to exist.

• A wine bar in Los Angeles: There is a wine bar called "The Red Room" in downtown Los Angeles, according to Yelp. This is another example of a nightclub or bar that uses "Red Room" as its name.

In summary, the term "red room" can have different meanings depending on the context, and it is not specific to nightclubs.