I think you mean to say degree of a monomial.
When you say Degree of a monomial, it is the sum of exponents of all its variables.
This is an example of a degree of a monomial:
The degree of the monomial 7y^3z^2 is 5(=3+2)
If a polynomial has more than one variable, then the degree of that monomial is the sum of the exponents of those variables.