Cornish mining. Also vugg, vugh, voog. [ad. Cornish vooga (Williams); cf. VOGAL.] A cavity in a rock; a cave, a hollow.
1818. W. Phillips, Geol., 207. The sound which the miner hears, may reasonably be accounted for by presuming him to be at work in the immediate neighbourhood of a cavity, or as he terms it, a voog.
1838. Mrs. Bray, Tradit. Devon., III. 256. It is not uncommon in deep mines, where there are what the miners term vugs … to hear loud and frequent explosions.
1855. J. R. Leifchild, Cornwall Mines, 92. Above this mixed mass, and in the level above, a great cavity (called by miners a vugh) was found.
1883. Encycl. Brit., xvi. 445/2. Dynamite … is very effective even in ground full of ‘vughs’ or cavities.
Hence Vuggy (also vughy) a., full of cavities.
1864. W. W. Smyth, Catal. Min. Coll. Museum Pract. Geol., 12. The lode is full of cavities, or ‘vuggy’ (as the Cornish miners term it).
1883. Gresley, Gloss. Coal-M., 273. Vughy rock, a stratum of cellular structure, or one containing many cavities.
