from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A sinkhole; a shakehole.
- n. Water breaking in upon the miners at their work.
from the GNU version of the Collaborative International Dictionary of English
- n. Water breaking in upon the miners at their work; -- so called among tin miners.
Compare German Schwall a sea swell, from schwellen to swell. See English swell. (Wiktionary)