The term "cosh" refers to a mathematical function known as the hyperbolic cosine. It is denoted as cosh(x) and is defined as the average of the exponential function e^x and its inverse e^(-x). The function is commonly used in various fields, including physics and engineering, to model certain types of waveforms and shapes. In addition to its mathematical meaning, "cosh" can also refer to a type of blunt weapon, often used in self-defense. This object is typically made of a heavy material and is designed to incapacitate an opponent without causing permanent harm. The use of a cosh as a weapon is often associated with criminal activity and is illegal in many places.