Stair n.
  1. One step of a series for ascending or descending to a different level; -- commonly applied to those within a building.
  2. A series of steps, as for passing from one story of a house to another; -- commonly used in the plural; but originally used in the singular only. “I a winding stair found.”
  Below stairs, in the basement or lower part of a house, where the servants are.
  Flight of stairs, the stairs which make the whole ascent of a story.
  Pair of stairs, a set or flight of stairs. -- pair, in this phrase, having its old meaning of a set. See Pair, n., 1.
  Run of stairs Arch., a single set of stairs, or section of a stairway, from one platform to the next.
  Stair rod, a rod, usually of metal, for holding a stair carpet to its place.
  Up stairs. See Upstairs in the Vocabulary.
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