to move in a tapering or conical way [v SPIRALED or SPIRALLED, SPIRALLING, SPIRALS]
Winding in a continuous and gradually widening (or tightening) curve, either around a central point on a flat plane or about an axis so as to form a cone
Winding in a continuous curve of constant diameter about a central axis, as though along a cylinder; helical
(of a staircase) Constantly turning in one direction as it rises, around a solid or open center
to move like a spiral (a type of plane curve) [v SPIRALED, SPIRALING, SPIRALLED, SPIRALLING, SPIRALS]
(of a fracture) Curving around a long bone lengthwise