#stair__step  support consisting of a place to rest the foot while ascending or descending a stairway; "he paused on the bottom step"
  supertype:  support.device  any device that bears the weight of another thing; "there was no place to attach supports for a shelf"
  subtype:  corbel_step  (architecture) a step or step-like projection on the top of a gable wall
  part of:  stairway
  part:  riser  structural member consisting of the vertical part of a stair or step
  part:  tread  structural member consisting of the horizontal part of a stair or step

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