[syn: tuff, tufa]
The Collaborative International Dictionary of English v.0.48:
Tufa \Tu"fa\, [It. fufo soft, sandy stone, L. tofus, tophus. Cf.
Tofus, Toph, and Tophin.] (Min.)
(a) A soft or porous stone formed by depositions from water,
usually calcareous; -- called also calcareous tufa.
(b) A friable volcanic rock or conglomerate, formed of
consolidated cinders, or scoria.
WordNet (r) 3.0 (2006):
n 1: a soft porous rock consisting of calcium carbonate
deposited from springs rich in lime [syn: tufa, calc-
2: hard volcanic rock composed of compacted volcanic ash [syn: