Definition:Associate

Let $$\left({D, +, \circ}\right)$$ be an integral domain.

If two elements of $$D$$ are both divisors of each other, then they are called associates.

That is, if $$x \backslash y$$ and $$y \backslash x$$, then $$x$$ is an associate of $$y$$.

Notation
The notation $$x \cong y$$ is sometimes seen to indicate that $$x$$ is an associate of $$y$$.