A staircase part is composed of several components, including a RISER (5 letters), newel (5 letters), BANISTER (8 letters), STEP (4 letters), TREAD (5 letters), and RAIL (4 letters). The RISER is the vertical part of the stair that connects the treads. The newel is the post at the beginning and end of the staircase. The BANISTER is the handrail along the side of the stairs. The STEP is the horizontal part of the stair that you STEP on. The TREAD is the part of the STEP that you actually walk on. The RAIL is the part of the BANISTER that runs along the side of the stairs.