Opposite of blessed. Cursed objects usually have bad effects. Cursed equipment (armor, rings, etc) generally can't be removed in the normal fashion, and cursed wands, potions, or scrolls often backfire or have limited effect. To curse an item, dip it in unholy water.

To uncurse an item, dip it in holy water. The spell "remove curse", in scroll form or if cast on you, will uncurse a random item. If you are in big trouble from a cursed item, such as an amulet of strangulation or boots of levitation, pray to your god.