A spin may be defined as an aggravated stall that results in what is termed "autorotation" wherein the airplane follows a downward corkscrew path. As the airplane rotates around a vertical axis, the rising wing is less stalled than the descending wing creating a rolling, yawing, and pitching motion. The airplane is basically being forced downward by gravity, rolling, yawing, and pitching in a spiral path.
PHAK Ch-04 (36) Spins
AC 61-67C Chapter3. Flight Training: Spins
AFH Ch-04 (13) Spin Awareness, Spin Procedures, Intentional Spins
Cessna 172 PIM Section 2
Cessna 172 PIM Section 3-32 Spin Recovery Checklist
Cessna SOPM 1-132 Spin Recovery Checklist
Private Pilot ACS Page 43 Task D. Spin Awareness