WoW is definitely addictive. When you choose your college class times to fit around raid times, you consider time spent not playing WoW to be wasted, you consider "but I might get a piece of t6" an excuse for not spending time with your girlfriend, you actually do 25 daily quests every single day, your time not spent playing WoW you spend reading about WoW, yeah, you're addicted.
Note, not all of the above have applied to me, but I know people/have heard stories of people they have applied to. And yeah, the most accurate term is addictive. But it's the nature of the game. As David Sirlin pointed out in this article -> http://www.gamasutra.com/features/20060222/sirlin_01.shtml it's the nature of the game. The more time you spend playing it, the more you get out of it. This makes people with the sorts of personalities prone to getting hooked on things easy pickings.