provoke
To deliberately make someone react, usually by getting angry.
To provoke means to deliberately cause a reaction, especially anger or annoyance. When you provoke someone, you say or do something on purpose to get them upset or make them respond. A younger sibling might provoke their older brother by repeatedly poking him or hiding his homework, trying to make him lose his temper.
Sometimes provoke means stirring up strong feelings that aren't necessarily angry ones. A powerful photograph might provoke deep thought about an important issue. A teacher might ask a provocative question designed to make students think hard and discuss different viewpoints. A speech can provoke debate when it challenges people's usual way of thinking.
The word often suggests deliberate action. If you accidentally bump into someone, that's not provoking them. But if you keep bumping them after they've asked you to stop, you're provoking a confrontation. Animals can provoke each other too: a dog might growl to provoke another dog into backing down, or a cat might swat at a dog to provoke a chase.
When something is described as unprovoked, it means it happened without any reason or trigger, like an unprovoked attack where someone started a fight for no reason at all.