Wildly violent, random, completely unpredictable behavior.
In the case of the woman to whom I was married for 19 years, I can attest that approximately three-fourths of the time it would be caused by something utterly out of my control. Someone else would say or do something--and she'd go ballistic on me. Admittedly, about one-fourth of the time, this behavior would come after something I said.
My words, although sometimes not advisable, were virtually never thoughtless. And I might say something one day that had no effect, while another day it would produce an unexpected, maniacal rage. (Smashing flower pots, throwing items at me, screaching like a woman being murdered...) Can you understand how such a thing makes it difficult to open up and be honest with someone? Or how pathetic it is that--even though I knew her behavior was irrational--I still felt guilt at how anything I might've said had "caused" this?
After years, I came to realize that I was experiencing much the same thing as a "battered woman." I was so frightened of this woman, that my own identity was stunted for years. I did not know who I was or what I wanted. I only lived to try to prevent her eruptions--and the effect they might have on our daughter.
If you can believe this, it was even more damaging than my relationship with the Watchtower Society. But the fact that this organization prevented me from seeking a separation or divorce from this troubled woman made things even worse.