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

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

Making jumpy decisions when under the cosh is not the way to survive a trial at Tynecastle, but that's what Murray did when bringing down Braga for Shankland's penalty.

From BBC • Oct. 26, 2025

Australia had been under the cosh for seven or eight minutes but hadn’t conceded and went into the break 7-3 down.

From BBC • Nov. 24, 2024

With deflation setting in and growth slowing, it's little surprise that China's stocks, bonds and currency are under the cosh.

From Reuters • Jul. 9, 2023

Sheep's vool shtickin' by der fences efferwhere on der ranch, py cosh!

From The Flying U Ranch by Bower, B. M.

Related Words

• bash
• bludgeon
• clobber
• pummel
• whack