Rectilinear means related to a straight line; it may refer to: Rectilinear grid, a tessellation of the Euclidean plane Rectilinear lens, a photographic lens Rectilinear locomotion, a form of animal locomotion Rectilinear polygon, a polygon whose edges meet at right angles Rectilinear propagation, a property of waves Rectilinear Research Corporation, a now defunct manufacturer of high-end loudspeakers Rectilinear style, the third historical division of English Gothic architecture Rectilinear motion or linear motion is motion along a straight line Rectilinear prophecy, where a straight line can be drawn from the prophecy to the fulfillment without any branches as in the case of typological interpretations Near-rectilinear halo orbit, a highly-elliptical orbit around a Lagrangian point of a moon, that due to the moons orbital movement, will be nearly rectilinear in some frames of reference. See also Linear (disambiguation) Straight (disambiguation)