That seems like a very reasonable definition to me. To your expanded definition: there's plenty of 'contentious' discussions that could happen on Hackernews fo

That seems like a very reasonable definition to me. To your expanded definition: there's plenty of 'contentious' discussions that could happen on Hackernews for example and I'm very glad that dang's excellent moderation and the community culture as a whole prevents them from overwhelming everything else as much as possible. Some subjects have the tendency to be very passionate and personal and to take over spaces when they appear, and letting every thread devolve into those topics makes for an unpleasant place. But the original definition requires it be "rude, disrespectful or unreasonable". So I don't think a controversial topic is necessarily toxic by their definition, though some topics tend to turn toxic very fast. These adjectives all pretty uncontroversially negative. The HN guidelines say "Be kind. Don't be snarky". Saying that a rude comment is toxic is just correct. If your terse comment or off-color joke is rude or unreasonable it Is toxic and you probably shouldn't say it.