Quintic equation refers to a polynomial equation that contains a term of the highest degree five. This equation is generally difficult to solve analytically and can be solved mainly by numerical methods. However, there are a few synonyms for the word quintic equation that describes it in different ways. Some of these synonyms are fifth-degree equation, degree-five polynomial, or polynomial of degree five. These synonyms differentiate quintic equations from other polynomial equations like quadratic, cubic, or quartic equations. Overall, each synonym describes the quintic equation in its unique way and helps in understanding its properties and characteristics.