## EnglishEdit

### EtymologyEdit

For Friedrich Bessel German mathematician

### NounEdit

**Bessel function** (*plural* **Bessel functions**)

- (mathematics) Any of a class of functions that are solutions to a particular form of differential equation (a Bessel equation) and are typically used to describe waves in a cylindrically symmetric system.

#### Related termsEdit

- Bessel function of the first kind
- Bessel function of the second kind