IPA: //ʌnprəˈvoʊkt//
KK: /ʌnˈproʊvoʊkt/
Something that happens without being caused or triggered by any action or event.
The dog bit him in an unprovoked manner, without any warning.
Unprovoked → It is formed from "un-" (meaning not) and "provocare" (from Latin, meaning to call forth or incite). The word "unprovoked" means not incited or not called forth, typically referring to an action that occurs without any provocation.
Think of something that happens 'not' ('un-') because it was 'called forth' ('provocare') — that's why unprovoked means it happened without any incitement.