(neuroanatomy) The space between the arachnoid mater and the pia mater that surrounds the brain and spinal cord, through which the cerebrospinal fluid circulates and major blood vessels pass, and across which extend delicate trabeculae of connective tissue.

plural of space request

(transitive, intransitive) To format (a document) so that every other line is left blank, leaving sufficient whitespace for annotation (e.g. a teacher's corrections).

(anatomy) The space in the wrist bounded by the hamate, capitate, triquetral and lunate bones.

An opening made by the pupil in the eye.

(control engineering) A mathematical model of a physical system as a set of input, output and state variables related by first-order differential equations.

A manifold or topological space X on which G acts by symmetry in a transitive way.

The process, made possible by technological innovations in transportation and communication, by which distant places are brought closer together in terms of the time taken to travel (or send messages) between them.

Alternative spelling of spaceship

(mathematics) A topological space that has precisely one nontrivial homotopy group.