Capricious; adjective; subject to, led by, or indicative of a sudden, odd notion or unpredictable change; erratic.
From The Shawl by Louise Erdrich: “He became, for us, a thing to be avoided, outsmarted, and exploited. We survived off him as if he were a capricious and dangerous line of work. I suppose we stopped thinking of him as a human being, certainly as a father.”
After searching this word, I see that the narrator was describing his father as something dangerous and unpredictable. He and the siblings he was referring to saw their father as someone crazy.