Degree( f )
Degree returns the degree d_<f> of f (see Polynomials).
Note that this is only equal to the Euclidean degree in the polynomial ring P(R). It is not equal in the Laurent polynomial ring L(R).
gap> x := Indeterminate(Rationals);; x.name := "x";;
gap> Degree( x^10 + x^2 + 1 );
10
gap> EuclideanDegree( x^10 + x^2 + 1 );
10 # the default ring is the polynomial ring
gap> Degree( x^-10 + x^-11 );
-10
gap> EuclideanDegree( x^-10 + x^-11 );
1 # the default ring is the Laurent polynomial ring
GAP 3.4.4