This definition was from WIKIPEDIA so no promises here...just reference, eh!
Liminality (from the Latin word līmen, meaning "a threshold" is a psychological, neurological, or metaphysical subjective, conscious state of being on the "threshold" of or between two different existential planes, as defined in (a "liminal state") and in the anthropological theories of ritual by such writers as Arnold van Gennep, Victor Turner, and others. In the anthropological theories, a ritual, especially a rite of passage, involves some change to the participants, especially their social status.The liminal state is characterized by ambiguity, openness, and indeterminacy.
One's sense of identity dissolves to some extent, bringing about disorientation. Liminality is a period of transition where normal limits to thought, self-understanding, and behavior are relaxed - a situation which can lead to new perspectives.
People, places, or things may not complete a transition, or a transition between two states may not be fully possible. Those who remain in a state between two other states may become permanently liminal.
Citations are needed for the above statements.