Skip to my tl;dr if you don't want to read my wall of text. Nowhere in my post did I say that abortion is, by definition, murder. I said that it fits all other definitions (well, qualifications, really) EXCEPT illegality. Yes. It SHOULD be classified as murder. And illegality is a poor reason for disqualifying something as murder. This is because legality is highly subjective, because it's more about what a group of people (The SCOTUS, in America's case) believes, and not based on facts. Premeditated? Objective, undisputable fact. Killing of another human being? Objective, undisputable fact. By another? Objective, undisputable fact. Lawfulness? Up to government's interpretation. Fact? Maybe, but not objectively so. Since it meets every other criterion, I believe it should be classified as murder.
tl;dr - Unlawfulness is subjective, everything else is not. Since abortion meets every other qualification that is factually based, it should be seen as murder.