spiral casing

noun

a spiral passage for directing the water from a penstock around a water turbine and into the rotor.

Discover More

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

In a few minutes a small hermit crab skittered toward the shell, probed the opening with its claws to measure the size of the interior space and rotated the spiral casing several times to look for holes.