WordGarden.iocosh
C2Pronunciation
UK
- /kˈɒʃ/
US
Meanings
Noun
a short heavy stick used as a weapon
the hyperbolic cosine function
Verb
to hit someone with a cosh
Beyond the definition
To cosh someone means to hit them hard, usually on the head, often with a short, heavy object. It's mostly a British word and often appears in crime stories or newspaper reports. A thief might cosh a guard before making an escape.
As a noun, a cosh is the weapon itself — a short, thick, often weighted club used to strike someone. It's associated with street crime or old police gear.
In mathematics, however, cosh has a completely different meaning. It's short for hyperbolic cosine, a function used in advanced algebra and calculus. So depending on the context, you might encounter cosh in a detective novel… or in a math textbook.
The word cosh lives a double life — one in the gritty world of crime fiction, and another in the precise language of mathematics.
In British English, to cosh someone means to strike them forcefully, especially on the head. It implies a sudden, heavy blow — often intended to knock someone unconscious. For example:
- "The burglar coshed the watchman and fled."
- "He was found unconscious after being coshed from behind."
The noun cosh refers to the weapon used — a short, dense club, sometimes filled with lead or sand to increase its weight. It's closely related to the term blackjack in American English. Historically, coshes were associated with criminals, though similar short clubs were also used as batons.
This meaning gives the word a sharp, violent tone. You wouldn't use it casually; it belongs mostly in crime reporting, historical contexts, or fiction.
Then suddenly, in a completely different universe, cosh appears in mathematics. It is the abbreviation for hyperbolic cosine, written as . In calculus and engineering, hyperbolic cosine is defined as:
It's used in physics, architecture, and engineering — for example, in describing the curve of a hanging cable (a catenary curve). Unlike the ordinary cosine function related to triangles and circles, hyperbolic cosine relates to hyperbolas.
So the same word can describe either a brutal blow in a dark alley… or a smooth curve in an engineering diagram.
Context, as always, makes all the difference.
Examples
- 1
Crime context
The robber pulled out a cosh and told the cashier to open the till.
- Usagea cosh
a short heavy weapon, especially in British English
- 2
Detective story
In the detective novel, the night watchman is coshed from behind and wakes up hours later.
- Grammarbe coshed
be hit with a cosh
- 3
Street attack
The mugger tried to cosh him, but he managed to run away.
See also
Forms and spellings
1 form open this card.
Main spelling
- coshnounverb