Synonyms and related words :
abutter, adjoiner, air line, approach, asymptote, axis, beeline, borderer, bottleneck, bystander, chord, collision course, concentralization, concentration, concourse, concurrence, confluence, conflux, congress, convergence, converging, crossing, diagonal, diameter, direct line, directrix, edge, focalization, focus, funnel, great-circle course, hub, immediate neighbor, looker-on, meeting, mutual approach, narrowing gap, neighbor, neighborer, normal, onlooker, perpendicular, radius, radius vector, right line, secant, segment, shortcut, side, spokes, straight, straight course, straight line, straight stretch, straightaway, streamline, transversal, vector