Question

what are polynomials​

Answer 1

an expression of more than two algebraic terms, especially the sum of several terms that contains different power on same variables

Answer 2

A polynomial is an expression containing two or more algebraic terms. They are often the sum of several terms containing different powers (exponents) of variables. What does 'polynomial' mean?

The "poly" in polynomial comes from Greek and means "multiple." "Nomial", also Greek, refers to terms, so polynomial means "multiple terms."