noun

• (countable, mathematics) A subset of a space which is a space in its own right.
• (uncountable, science fiction) Any (often unspecified) method of communicating or travelling faster than light speed.
• (uncountable, science fiction) An alternative dimension or universe, access to or use of which permits faster-than-light travel or communications; hyperspace.
• (BDSM) The psychological state of the submissive or "bottom" during sadomasochistic activity.