Easton's Bible Dictionary
Denounced by God against the serpent (Genesis 3:14), and against Cain (4:11). These divine maledictions carried their effect with them. Prophetical curses were sometimes pronounced by holy men (Genesis 9:25; 49:7; Deuteronomy 27:15; Joshua 6:26). Such curses are not the consequence of passion or revenge, they are predictions.
No one on pain of death shall curse father or mother (Exodus 21:17), nor the prince of his people (22:28), nor the deaf (Leviticus 19:14). Cursing God or blaspheming was punishable by death (Leviticus 24:10-16). The words "curse God and die" (R.V., "renounce God and die"), used by Job's wife (Job 2:9), have been variously interpreted. Perhaps they simply mean that as nothing but death was expected, God would by this cursing at once interpose and destroy Job, and so put an end to his sufferings.
Noah Webster's New International Dictionary of the English Language
1. (v. t.) To call upon divine or supernatural power to send injury upon; to imprecate evil upon; to execrate.
2. (v. t.) To bring great evil upon; to be the cause of serious harm or unhappiness to; to furnish with that which will be a cause of deep trouble; to afflict or injure grievously; to harass or torment.
3. (v. i.) To utter imprecations or curses; to affirm or deny with imprecations; to swear.
4. (n.) An invocation of, or prayer for, harm or injury; malediction.
5. (v. t.) Evil pronounced or invoked upon another, solemnly, or in passion; subjection to, or sentence of, divine condemnation.
6. (n.) The cause of great harm, evil, or misfortune; that which brings evil or severe affliction; torment.