Definition of alcoholism?

I grew up fearing I would become an alcoholic like my mother bc I always heard "she can't help it." I do enjoy drinking socially (few times a year). To alleviate my fears, I stuck with a definition of alcoholism that made sense to me as a child. "If alcohol is creating problems in your life, you're an alcoholic." I now find myself engaged and living with a man who treats me and my children very well. One year after dating, we moved in together. That's when I realized he had a drinking problem. Black outs, pass outs, sick, unable to have sex anymore, etc. One year after living together, I still don't know how much bc he hides it. He has promised and tried to stop several times. I've threatened to leave and watched him struggle to quit. It never lasts longer than a week and he has never gone a day without a drink. No one knows he has a problem, the children don't realize it and he has never once raised his voice to me or been unkind. He is successful, active, etc. I did not know alcoholism could be like this and I feel I am the only one with a problem with it. Now my childhood definition no longer satisfies me. "If alcohol is creating problems in your life, you're a ______" Co-Dependent. Fiance. Mother. Brother. Friend. Grandson. Daughter. Fill in the blank. As I search for sense in this, I conclude "If you try to stop drinking and can't, you're an alcoholic." Is that true? What is YOUR definition of alcoholism?