In the same vein as sussurus, I absolutely adore hubbub. A favorite useful word, which I take pleasure in being able to wield when it's convenient, is salient. It's similar to "relevant", but less judgemental, because it simply describes a topic which is already in the discourse context. One example might be if you were to ask a person to bring "the car" around. They would know which car you were referring to (probably the one they were in or the closest one they had access to), and that car would be the salient car in the context. It's a term from linguistics, but I actually use it all the time to halt derailings, real misunderstandings, and feigned confusion. Other than that, I'm a sucker for German compound words: - verschlimmbessern, from verschlimmern ("to make worse") and verbessern ("to make better"), which describes when you make something worse while trying to make it better. There's also supposedly kaputtreparieren ("to break something while trying to fix it"), though I've never caught that one in the wild. - Fremdschämen ("external shame") is that feeling you get when watching someone who should be really, really embarrassed but maybe isn't and you're humiliated on their behalf. - Vergangenheitsbewältigung is a uniquely German concept, by my reckoning. Literally "the process of coming to terms with the past", but you can probably guess at what sort of "past" is salient in the German context (Nazism).
I spent today doing kaputtreparien!
I drove my car to the garage and, in doing so, totaled the engine. I was feeling horrible about this until I found this perfect word for it, and now I feel like Germany understands my pain :)