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 trilobite fossils were trapped between layers of petrified ash in sandstone, the product of old volcanic eruptions that settled on the sea floor and formed a green layer called a tuff.

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

The area is known for its Bishop tuff — a type of rock formed by super-heated volcanic ash, which is of interest to researchers.

From Los Angeles Times • Jul. 19, 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