spiral down
1. To travel down (something) in a twirling or spiraling motion. After the second engine went dead, the plane started spiraling down to the ground. I pulled the plug and watched the water spiral down the drain.
2. Of some measurement or value, to decrease very rapidly. The company's stock prices have spiraled down since the CEO's arrest, dropping nearly 18 points in two days. As the sun set the temperature began spiraling down, so I knew we needed to find shelter soon.
spiral down
to descend in a spiral path. The ancient trail spiraled down the mountain peak. A path spiraled down and at the bottom was a small refreshment stand.