Merriam-Webster Collegiate Dictionary - stair

 biographical name Viscount & Earl of — see Dalrymple STAIR  noun  Etymology: Middle English steir, from Old English st?ger; akin to Old English & Old High German stigan to rise, Greek steichein to walk  Date: before 12th century  1. a series of steps or flights of steps for passing from one level to another — often used in plural but sing. or plural in constr. a narrow private ~s — Lewis Mumford  2. a single step of a ~way