\begin{definition}[Definition:Associate/Integral Domain/Definition 1]
Let $\struct {D, +, \circ}$ be an integral domain.
Let $x, y \in D$.
'''$x$ is an associate of $y$ (in $D$)''' {{iff}} they are both divisors of each other.
That is, $x$ and $y$ are '''associates (in $D$)''' {{iff}} $x \divides y$ and $y \divides x$.
\end{definition}