from The American Heritage® Dictionary of the English Language, 4th Edition
- n. An opening in the earth from which carbon dioxide and other gases escape, usually marking the last stage of volcanic activity.
- n. The gases escaping from such an opening.
from The Century Dictionary and Cyclopedia
- n. An irrespirable gas escaping from the earth; a gas-spring.
French, gaseous exhalation, from Italian moffetta, diminutive of muffa, mold, moldy smell, probably of Germanic origin.(American Heritage® Dictionary of the English Language, Fourth Edition)