rectilineal

/R EH1 K T IH0 L IH1 N IY0 AH0 L/
adjective
  1. 1

    In a straight line.

    โ€œThe crankshaft and connecting rods of an engine convert the rectilinear motion of the pistons to rotary motion of the flywheel.โ€

  2. 2

    Formed from straight lines.

Source: https://en.wiktionary.org/wiki/rectilineal, https://en.wiktionary.org/wiki/rectilinear