Incidental/ˌɪnsɪˈdentl/ Definition 1 of 3Pro Tip 1/3Unexpected Result Occurs by chance and isn't planned within the main activity. Finding the old coin was an incidental benefit of cleaning the garage. Pro Tip 2/3Not Central Not the main focus, but related to the main event or activity. Our discussion led to an incidental debate on related topics. Pro Tip 3/3Unintended Occurrence Not intentionally included or planned; happens by the side. The new client we met was an incidental occurrence during our business trip.