a person who rises, especially from bed: to be an early riser.
the vertical face of a stair step.
any of a group of long boards or narrow platforms that can be combined in stepwise fashion: The choir stood on a horseshoe of risers behind the orchestra.
a vertical pipe, duct, or conduit.
Metallurgy. a chamber or enlarged opening at the top of a mold for allowing air to escape or adding extra metal.
6. Nautical. a.
a heavy strake of planking in the vicinity of the garboard strake in a wooden vessel.
Origin: 1350–1400; Middle English;