unprovoked

/ˌʌnprəˈvoʊkt/
adjective
  1. Happening without any apparent reason or cause; not triggered by something else.
    • He received an unprovoked insult from a stranger on the bus.
    • The country faced an unprovoked invasion by its neighbor.
    • The dog's unprovoked attack on the mail carrier surprised everyone.
Antonyms
What does "unprovoked" mean? | whatsthatwordmean | whatsthatwordmean