ris‧er /ˈraɪzə $ -ər/ noun [countable]

1. early/late riser someone who usually gets out of bed very early or very late

2. technical the upright part of a step on a set of stairs

3. risers [plural] American English a set of wooden or metal steps that can be moved from place to place, used for a group of people to stand on:
The school choir stood on risers behind the orchestra.

[TahlilGaran] Dictionary of Contemporary English ▲