\Stair\, n. [OE. steir, steyer, AS. st?ger, from ?igan to
ascend, rise. [root]164. See {Sty} to ascend.]
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.'' --Chaucer's Dream.
{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 stars} (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.