A curse was a powerful magical effect placed upon a person, place, or object. Curses could have a wide variety effects, but were generally negative or harmful; they often involved weakening, injuring, or thwarting the intentions of an afflicted individual or by destabilizing an afflicted item. In general, a curse was hard to remove, and only a handful of specialized Spells could hope to remove even a weak curse.
A more powerful curse needed great power to remove, if it was possible to remove at all.