Part of a flight is an important part of the journey, and there are several terms associated with it. STAIR (5 letters) is a set of steps leading from one level to another. STEP (4 letters) is a single movement in climbing or descending a STAIR. RISER (5 letters) is the vertical face of a STEP. Embarcate (9 letters) is the process of boarding a plane. Stairstep (9 letters) is a series of steps that form a staircase.