My Bible has a footnote on Job 1:5 that says the word "curse" in this passage is actually the Hebrew word for "bless." I don't understand this.
"So it was, when the days of feasting had run their course, that Job would send and sanctify them, and he would rise early in the morning and offer burnt offerings according to the number of them all. For Job said, "It may be that my sons have sinned and cursed God in their hearts." Thus Job did regularly" (Job 1:5).
The Hebrew word barak at its root means to kneel. It can be seen in "And he made his camels kneel down outside the city by a well of water at evening time, the time when women go out to draw water" (Genesis 24:11) where "made to kneel" is the Hebrew word barak.
From there it came to include the idea of giving greeting or farewell, as it can be seen in I Samuel 13:10; 25:14; II Kings 4:29. Some suspect that this led to the general usage of giving a blessing, or in rarer cases dismissing or rejecting a person. It is in this latter idea that it appears to be used in Job. Barak is not being used to say that that they actively called curses on God during the party, but that Job was concerned that in their celebration that they forgot about God for a time. This then makes better sense in what Satan claims. "But now, stretch out Your hand and touch all that he has, and he will surely curse You to Your face!" (Job 1:11). He is saying that Job would dismiss or reject God if his blessings were removed (see also Job 2:5). This same meaning makes sense for what Job's wife said. "Then his wife said to him, 'Do you still hold fast to your integrity? Curse God and die!'" (Job 2:9). She is saying reject God, dismiss Him, get Him out of your life, and die.
Though naqab is the usual word for "curse" in the Hebrew language, it was barak that Naboth was accused of committing. "And seat two men, scoundrels, before him to bear witness against him, saying, "You have blasphemed God and the king." Then take him out, and stone him, that he may die. ... And two men, scoundrels, came in and sat before him; and the scoundrels witnessed against him, against Naboth, in the presence of the people, saying, "Naboth has blasphemed God and the king!" Then they took him outside the city and stoned him with stones, so that he died" (I Kings 2:10, 13). The word "blasphemed" in the New Kings James version is too strong of a rendering. Many other translations say "curse." But even here we can see that the accusation is that Naboth rudely rejected both God and the king.
Thus, the proper translation depends on the context in which the word is being used. Generally, it is "blessed" but when used in a negative sense, it is a "curse." But not a vile calling of sacrilegious words on a person, but rejection or rude dismissal of one who should be respected.