tuff

¹ American  

[tuhf] / tʌf /

adjective

Slang.

1. tough.

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tuff ² American  

[tuhf] / tʌf /

noun

Geology.

1. a fragmental rock consisting of the smaller kinds of volcanic detritus, as ash or cinder, usually more or less stratified.

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tuff British  

/ tʌf, tʌˈfeɪʃəs /

noun

1. a rock formed by the fusing together on the ground of small rock fragments (less than 2 mm across) ejected from a volcano

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tuff Scientific  

/ tŭf /

1. A rock made up of particles of volcanic ash, varying in size from fine sand to coarse gravel.

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Other Word Forms

• tuffaceous
  adjective

Etymology

Origin of tuff

1560–70; < French tuf < Italian tufo. See tufa

Example Sentences

The petroglyphs can be found on volcanic tuff formations formed over 760,000 years ago when a large eruption released hot ash that settled over the region.

From Los Angeles Times • Mar. 11, 2025

In her laboratory in Basel, Wojtczak compared these samples from the cave with tuff she had worked on experimentally with wood, bone and stone tools, as well as with her hands.

From Science Daily • Nov. 21, 2023

The river tracks a diverse landscape from the southern edge of the Rocky Mountains through rugged basalt hillsides, layers of volcanic tuff, and the red and yellow cliffs made famous by painter Georgia O’Keeffe.

From Seattle Times • Sep. 18, 2021

"And 'meeting/trusting' people in my position is really tuff," she noted.

From Fox News • Oct. 5, 2019

“Yo, that was kinda tuff, though. We should add that to the routine when we get home.”

From "Monday's Not Coming" by Tiffany D. Jackson