To stir up trouble is to deliberately cause difficulty between people. He came to stir up trouble.
The deliberateness is the point, which is what separates it from causing trouble by accident. It is used of a person rather than of an event.
1phrasestir up troubleTo deliberately cause difficulty between people.
“She repeated it around the office to stir up trouble.”
stir up trouble is a phrase.
Practised in Idioms