What is the definition of a monomial?

A monomial is a mathematical expression that consists of a single term, which can be a number, a variable, or the product of numbers and variables raised to non-negative integer exponents. In its simplest form, a monomial takes the shape of ( ax^n ), where ( a ) is a coefficient, ( x ) is a variable, and ( n ) is a non-negative integer. Monomials do not include addition or subtraction of different terms. Examples include ( 4x^3 ), ( -2y ), and ( 7 ).