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