from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The calcareous and siliceous rock deposits of springs, lakes, or ground water.
- n. See tuff.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. the calcareous deposit of lime found near hot springs
- n. the volcanic rock tuff
from the GNU version of the Collaborative International Dictionary of English
- A soft or porous stone formed by depositions from water, usually calcareous; -- called also calcareous tufa.
- A friable volcanic rock or conglomerate, formed of consolidated cinders, or scoria.
from The Century Dictionary and Cyclopedia
- n. A rock having a rough or cellular texture, sometimes a fragmental volcanic material, and sometimes a calcareous deposit from springs.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. hard volcanic rock composed of compacted volcanic ash
- n. a soft porous rock consisting of calcium carbonate deposited from springs rich in lime
Obsolete Italian tufa, tufo, from Latin tōfus.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Italian tufo, from Latin tōphus or tōfus. (Wiktionary)