If it had only 1 term it would be a MONOMIAL. If it had only 2 terms it would be a BINOMIAL. If it had only 3 terms it would be a TRINOMIAL. But yours has 4 terms. So all you can do is say it is a POLYNOMIAL. For some reason they never coined a word "quadranomial" or "tetranomial", :) For all I know, in other languages there may be a word specifically for 4-term polynomials, but not in English. So we just call it a polynomial. FYI, its degree is 7. Edwin