'Curse' in the Bible

hereby participate with their colleagues the town leaders and enter into a curse and an oath to adhere to the law of God which was given through Moses the servant of God, and to obey carefully all the commandments of the LORD our Lord, along with his ordinances and his statutes.

for they had not met the Israelites with food and water, but instead had hired Balaam to curse them. (Our God, however, turned the curse into blessing.)

So I entered a complaint with them. I called down a curse on them, and I struck some of the men and pulled out their hair. I had them swear by God saying, "You will not marry off your daughters to their sons, and you will not take any of their daughters as wives for your sons or for yourselves!