I have an algorithm (based on heuristics) that solves for a quantity $x$, producing a practically good result but not guaranteed to be optimal.
What adjective can I use to describe this "solution" $x$? "Suboptimal" has a negative connotation. I want to communicate that $x$ is good and useful although not the best possible.
This is not really a mathematical question. You could try "near optimal" or "satisficing".