Ais a monomial or the sum or difference of two or more monomials. base, polynomial, linear term, quadratic equation

The answer is:

 "A polynomial is a monomial or the sum or difference of two or more monomials".

 By definition, the terms of a Polynomial Function have the form ax^n, where "n" is a natural number. 

 To classify a polynomial, you must count the number of its terms. For example:

 5x²-2x  (This is a binomial, because it is formed by two terms).
 x³-3x+1 (This is a trinomial, because it has three terms):

 To identify the degree of a polynomial, you must see the term which has the highest exponent. For example, the degree of following polynomial is 2.

 4x²-x+3 

 The degree of this polynomial is 3:

 x³+2x²-x+10