Hedonism, as a philosophical term (the original usage of the word), is a school of thought in which the things that can be felt, pleasure or pain, are either the primary or sole indicators of moral goodness. Typically the idea is that which causes pleasure is good, and that which causes pain is evil, though there are variations of it. The central aspect that ties those variations together is the idea that consequences of pleasure and suffering are the things that should be considered in ethical decisions.
Terminal insists that a fetus not being a "thinking, feeling person" is of moral significance, that the "thinking, feeling" part is why we don't murder people, and without it there's nothing wrong with killing. If the unborn can't feel the pain, there's no moral reason not to have abortions. That is Terminal's stance, that is hedonism. That is not my stance, I would say we don't kill people because human beings have intrinsic value independent from their experience of life.