[stair] n [ME steir, fr. OE staeger; akin to OE & OHG stigan to rise, Gk steichein to walk] (bef. 12c) 1: a series of steps or flights of steps for passing from one level to another--often used in pl. but sing. or pl. in constr. "a narrow private ~s --Lewis Mumford"
2: a single step of a stairway