The term "twilight zone" originally came from the name of a popular TV show in the 1950s and 60s. The phrase has since become synonymous with a state of mind or a situation that is strange, eerie, or unsettling. Other terms that can be used as synonyms for "twilight zone" include "limbo," "no man's land," "purgatory," "netherworld," "unknown territory," and "ambiguous space." These phrases all convey a similar sense of being in a place or situation where one is unsure of what is happening or what will happen next. Whether used in literature, film, or everyday conversation, these terms all capture the feeling of being in a state of uncertainty or in-betweenness.