stair

A series or flight of steps; a staircase.

One of a flight of steps.

A step; a degree.

One of a series of steps to mount by: as, a flight of stairs.

A flight or succession of flights of steps, arranged one behind and above the other in such a way as to afford passage from a lower to a higher level, or vice versa: as, a winding stair; the back stair: often used in the plural in the same sense.

One step of a series for ascending or descending to a different level; — commonly applied to those within a building.

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.

in the basement or lower part of a house, where the servants are.

the stairs which make the whole ascent of a story.

a set or flight of stairs. — pair, in this phrase, having its old meaning of a set. See Pair, n., 1.