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]