Quartic a. : Of the fourth degree.

Quartic n. : A quantic of the fourth degree. See Quantic.

Quartic n. : A curve or surface whose equation is of the fourth degree in the variables.

Example:
How do I write cubic and Quartic functions based on two pieces of data?

Taxonomy
equation, quartic, polynomial, quartic function, coefficients, roots, perfect square, the roots, quartic equations, cubic equation, factor, right side, square root, quadratic function, sides, powers, equating coefficients, product.

Defination from the web:
quartic function is a polynomial of even degree, it has the same limit when the argument goes to positive or negative infinity. ... Quartic equations were first considered by Jaina Mathematicians in ancient India between 400 BC and 200 AD. ...