(physics) vacuum; a space free of matter. / Used other than figuratively or idiomatically: see free, space.

(mathematics) Euclidean space described by Cartesian coordinates.

Ordinary two- or three-dimensional space, characterised by an infinite extent along each dimension and a constant distance between any pair of parallel lines.

(idiomatic, UK) To introduce a problem, dilemma or obstacle, something unexpected or troublesome.

(computing) An open proxy used to send spam.

A bulbous iris, Iris xiphium, from the western Mediterranean; it has violet-purple flowers with a short perianth tube.

(chemistry) the set of all possible stable molecules

(originally) A person in training to be a (generally military) astronaut, especially in science fiction.

present participle of spank

Fast and energetic. / (often nautical) Brisk and fresh.