Stair \Stair\ (st[^a]r), n. [OE. steir, steyer, AS. st[=ae]ger, from st[imac]gan 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. [1913 Webster] 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. [1913 Webster] {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. [1913 Webster]