A polynomial containing three unlike terms.

### Examples

- The expression 3
*x*+*y*– 8 is a trinomial. - The expression \(a^{2} + 2ab + b^{2}\) is a trinomial.

### Etymological note

The term *trinominal* is derived from the Greek prefix *tri* (τρι) meaning *three*, and from the Greek word *nomos* (νομοσ), meaning *part*, *portion* or *division*. Therefore, a trinomial is an algebraic expression with three entities, three parts or three elements.