ETYM Cf. French spiral. Related to Spire a winding line.
1. Winding or circling round a center or pole and gradually receding from it.
2. Winding round a cylinder or imaginary axis, and at the same time rising or advancing forward; winding like the thread of a screw; helical.
3. Of or pertaining to a spiral; like a spiral.
Petit ressort d'horlogerie.