riser

noun

• Someone or something which rises.
• A platform or stand used to lift or elevate something.

  "The choir stood on risers for the performance."

• The vertical part of a step on a staircase.
• The main body of a bow.
• A vertical utility conduit, pipe or path between floors of a building for placement of cables (e.g. telephone, networking), or to convey fluids (e.g. gas, water).
• A pipe connecting an individual exhaust port of an internal combustion engine to the muffler, particularly on aircraft.
• A Manx cat with a showable short tail.
• A strip of webbing joining a parachute's harness to the rigging lines.