Search Result for "tuff": 
Wordnet 3.0

NOUN (1)

1. hard volcanic rock composed of compacted volcanic ash;
[syn: tuff, tufa]


The Collaborative International Dictionary of English v.0.48:

Tuff \Tuff\, n. (Min.) Same as Tufa. [1913 Webster]
WordNet (r) 3.0 (2006):

tuff n 1: hard volcanic rock composed of compacted volcanic ash [syn: tuff, tufa]