good times, noodle salad

So, what exactly does it mean to be open-minded? I like to think of myself as open-minded, but at the same time I realize that I'm incredibly opinionated about topics and issues that matter to me. So if I have a strong and unlikely to budge opinion about something I've researched well and thought about, am I still open-minded? I really can't think of issues that I feel passionately about that I haven't done the research to back up my opinion, and there are loads of things that I don't have much of an opinion on, and I consider myself to be open-minded about those topics as "the jury (in my mind) is still out." Is open-mindedness simply a willingness to hear various viewpoints, and consider their merit, even if you are pretty set in your own opinion?