It is impossible to know what the situation is just from a search engine phase. Could it be that the person's partner has an untreated mental illness like irritable depression, bipolar mania, OCD, or even PTSD? For different reasons, all of these can sometimes have as part of the symptom profile anger. On the other hand, is the person living with a batterer? Is there chronic illness or job loss stress? I could go on and on about the possibilities.
The bottom line is that no one should have to feel afraid of his or her partner. The person we love should make us feel safe and secure and visa versa. That is usually why most people get together. The person they love makes them feel good. When a situation has gotten to the point of feeling fear of a loved one it is time to take calm, focused, and planned action. Fear is a message from the body that things could be dangerous. It is time to stand up to the anger and to reach out and get help.
Online Domestic Violence Assessment
I found this resource for women in abusive relationships.