\begin{definition}[Definition:Content of Polynomial/GCD Domain]
Let $D$ be a GCD domain.
Let $K$ be the field of quotients of $D$.
Let $f \in K \sqbrk X$ be a polynomial.
Let $a \in D$ be such that $a f \in D \sqbrk X$.
Let $d$ be the greatest common divisor of the coefficients of $a f$.
Then we define the '''content''' of $f$ to be:
:$\cont f := \dfrac d a$
\end{definition}