riser

The vertical board or surface between two steps on a staircase.

"The wooden risers needed a fresh coat of paint."

A vertical pipe or duct carrying fluids or cables upwards in a building.

"Engineers checked the main water riser for leaks."

A person who gets out of bed, especially at a particular time.

"She is an early riser, always up before dawn."

A share or commodity whose market price is currently increasing.

"Technology stocks were among the day's biggest risers."