In modern usage, curse is generally considered synonymous with swear.
In the Bible curse takes on different meanings, such as to invoke misfortune, to afflict, to make an oath, and to insult, as well as to swear. Here are some ways curse is used in the Bible:
Curses, or ill-will, can be given to people (Canaan in Genesis 9:25), the disobedient (Jeremiah 11:3), a house (Job 5:3), animals (the serpent in Genesis 3:14), plants (the fig tree in Mark 11:12-14), and earth (Isaiah 24:6); the ground (Genesis 3:17); and the land (Hebrews 6:8).
Curse is the opposite of bless, Luke 6:28 and Romans 12:14.
The curse can also mean “to swear at”(Goliath cursed David), 1 Samuel 17:43.
When Peter denied knowing Jesus he swore and called down curses on himself, Matthew 26:74 and Mark 14:71.
A curse is sometimes the self-imposed penalty for failing to keep a promise or oath, Nehemiah 10:29 or Numbers 5:21.
Key verse about Curse: May nations serve you and peoples bow down to you. Be lord over your brothers, and may the sons of your mother bow down to you. May those who curse you be cursed and those who bless you be blessed” (Genesis 27:29, NIV).
A lifelong student of the Bible, Peter DeHaan, PhD, wrote the 1,000-page website ABibleADay.com to encourage people to explore the Bible. His main blog and many books urge Christians to push past the status quo and reconsider how they practice their faith in every area of their lives.