Riser

noun

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

   "The choir stood on risers for the performance."

3. The vertical part of a step on a staircase.
4. The main body of a bow.
5. 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).