: a rock composed of the finer kinds of volcanic detritus usually fused together by heat
tuffaceous adjective

Example Sentences

Recent Examples on the Web Perched on a brownish-red tuff promontory near the Umbrian border, Civita is a place where time stands still. Silvia Marchetti, CNN, 8 Sep. 2022 There are older consolidated rocks, loose volcanic tuff produced by explosive eruptions, and a variety of clays, which may or may not contain hot water. John Timmer, Ars Technica, 23 Mar. 2022 About halfway through the hike, the road swings around a water tank and begins a winding ascent through a geologically complex zone of quartzite, limestone and volcanic tuff — an amazing display 540 million years in the making. Mare Czinar, The Arizona Republic, 28 Feb. 2022 Slicing through Big Bend National Park, the narrow, two-lane road curves through cliffs of volcanic tuff and past Wild West ranches, ending at the spectacular 1,500-foot limestone walls of Santa Elena Canyon. Emily Pennington, Outside Online, 26 Aug. 2021 Interspersed with the in-person dancers are film sequences within the 400-feet-deep tuff quarry. BostonGlobe.com, 13 Oct. 2021 The area is known for its Bishop tuff — a type of rock formed by super-heated volcanic ash, which is of interest to researchers. Los Angeles Times, 19 July 2021 Fish Slough, a National Natural Landmark on the eastern edge of the tablelands, includes vivid petroglyphs chipped into bizarrely eroded volcanic tuff formations that overlook a verdant desert oasis laced with meandering spring-fed creeks. Los Angeles Times, 19 July 2021 For disposal in granite, clay and tuff formations the maximum allowable disposal density is determined by thermal limitations and most scenarios have waste canisters separated by about 8 feet. James Conca, Forbes, 27 Apr. 2021 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'tuff.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History


earlier tuph, tuft porous rock, from Middle French tuf, from Old Italian tufo

First Known Use

1815, in the meaning defined above

Time Traveler
The first known use of tuff was in 1815

Dictionary Entries Near tuff

Cite this Entry

“Tuff.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/tuff. Accessed 3 Dec. 2022.

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