helical stair

helical stair

A stair whose treads are wrapped around a helix: commonly called a spiral stair. See also: stair

spiral stair, caracole, circular stair, cockle stair, corkscrew stair, spiral staircase

spiral stair A flight of stairs, circular in plan, whose treads wind around a central newel. Also called a helical stair, solid newel stair.