滋事 is formal/legal — almost always seen in news, police reports, and the fixed phrase
寻衅滋事 (xúnxìn zīshì, 'picking quarrels and provoking trouble'), which is an actual offense in PRC criminal law (Article 293,
中华人民共和国刑法). Don't use it in casual speech; everyday equivalents are
闹事 (nàoshì) or
惹麻烦 (rě máfan).
