cosh

¹ American  

[kosh] / kɒʃ /

noun

1. a blackjack; bludgeon.

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verb (used with object)

1. to hit on the head with a cosh.

cosh ² American  

[kosh] / kɒʃ /

noun

Mathematics.

1. hyperbolic cosine.

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cosh ¹ British  

/ ˈkɒsˈeɪtʃ, kɒʃ /

noun

1. hyperbolic cosine; a hyperbolic function, cosh z = 1/ 2 (e z + e –z ), related to cosine by the expression cosh i z = cos z, where i = √–1

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cosh ² British  

/ kɒʃ /

noun

1. a blunt weapon, often made of hard rubber; bludgeon

2. an attack with such a weapon

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verb

1. to hit with such a weapon, esp on the head

cosh Scientific  

1. Abbreviation of hyperbolic cosine

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Etymology

Origin of cosh¹

First recorded in 1865–70; of uncertain origin; perhaps from Romani kosh, koshter “piece of wood,stick,” akin to Sanskrit kāṣṭham

Origin of cosh²

First recorded in 1870–75; cos(ine) + h(yperbolic)

Example Sentences

"There's no two ways about it - we were under the cosh," McInnes admitted.

From BBC • Apr. 11, 2026

Four-time major champion Sinner was imperious and looked unflustered on the few occasions that the aggressive Shelton put him under the cosh.

From Barron's • Jan. 28, 2026

It was McInnes' turn to weave the magic half-time wand, although he will also be pleased with Kilmarnock's resilience during a first half when they were under the cosh.

From BBC • Dec. 10, 2023

She told the BBC: "She felt under the cosh... No support was offered to her whatsoever."

From BBC • Jul. 13, 2023

"O bah cosh, see! das second time I catchum, Koskomenos."

From Secret of the Woods by Long, William Joseph

Related Words

• bash
• bludgeon
• clobber
• pummel
• whack