I actually agree, and have thought so for a long time, that the discussion about abortion is very much about the meaning of the term life.
One side is convinced that a human life starts at the conception. And if you think that, it is very simple: Abortion is taking a human life, i.e., killing a person. Then nothing else matters. We can bring up all social, economic, feminist, psychological, health, etc. arguments in the world, all in vain. We all agree that we don't go around and kill people, so if you think that life starts at the conception, there's nothing more to argue about.
So in this case, we disagree only about meaning. The only way to have fruitful discussion would be to talk about what we mean by a human life. Then I'm not sure that is possible when one side's main argument is "the Bible says so". But there's nothing inconsistent or contradictory that could be resolved between the premises "a human life starts at conception" and "taking a human life is always wrong", and the conclusion "abortion is wrong".