from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A small cavity in a rock or vein, often with a mineral lining of different composition from that of the surrounding rock.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A small to medium-sized cavity inside rock that may be formed through a variety of processes.
from The Century Dictionary and Cyclopedia
- n. In mining, a cavity; a hollow in a rock or in a lode. Vug is the miners' name for that which geologists more generally call a geode. See geode. Also called tick-hole, vooga-hole.
Cornish vooga.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Cornish vooga ("cave"). Compare fogou. (Wiktionary)