<p><strong>Adverb</strong></p><ul><li>apart or aside from the main subject of attention, discussion, etc.; by the way; parenthetically: "Incidentally, while you were waiting for the officer to run your registration through the system, did you notice if the post office was open?"</li><li>in the course of something else, and not intentionally: "The bone fractures were discovered only incidentally, during an unrelated CT scan of her chest."</li></ul><p><strong>End of Response</strong></p>