tailspin

Meanings

1. The rapid, uncontrollable descent of an aircraft in a steep spiral.
2. A severe mental or emotional collapse; emotional breakdown.
3. Any sharp, sustained, often uncontrollable descent or decline.

1. Of an aircraft: to go into a rapid, uncontrollable descent in a steep spiral.
2. To go into a sharp, sustained, often uncontrollable descent or decline.

Etymology

From tail + spin.