Synonyms and related words :
air line, axis, beeline, boil down, chord, diagonal, diameter, direct line, directrix, distill, edge, great-circle course, modernize, narrow, normal, oversimplify, perpendicular, purify, radius, radius vector, reduce, reduce to elements, refine, right line, secant, segment, shortcut, side, simplify, straight, straight course, straight line, straight stretch, straightaway, strip down, tangent, transversal, update, vector