from
The Collaborative International Dictionary of English v.0.48
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]