ETYM Poly- + -nomial, as in monomial, binomial: cf. French polynôme.
A mathematical expression that is the sum of a number of terms.
Mathematics, (expression) of more than one term; Biology, (name) of more than three terms.
In mathematics, an algebraic expression that has one or more variables (denoted by letters). A polynomial of degree one, that is, whose highest power of x is 1, as in 2x + 1, is called a linear polynomial.
3x2 + 2x + 1 is quadratic; 4x3 + 3x2 + 2x + 1 is cubic.

Having the character of a polynomial