Uncle

My "uncle" Amos died last week. He died of Parkinson's disease which he suffered from over fifteen years. I call him my "uncle" because I hardly ever met him. By the time I was seven years old he was already in a nursing home, I only have vague memories of him being pretty sick in my aunt's house in Israel. What do I call him, my uncle? He was my aunt's husband and my cousins' father, but not related to me by blood. I don't know.

I don't know how to feel about this. Is there a certain way I'm supposed to feel? I will call my aunt to wish her condolences, but she'll know it doesn't mean all that much. But anyways, I'm a little confused about all of this.