Swearing
To swear can mean either to make an oath, or to utter profanity.
A court witness will have to swear to tell the truth, sometimes by the name of a deity or upon things considered holy, for example a Bible or a Qur'an.
Use of this type of swearing in inappropriate or trivial circumstances, or in some traditions "taking the Lord's name in vain," is often considered wrong or sinful. The term swearing in common speech took on this meaning. Some current swearwords have this literal origin, either in straightforward use, e.g., for Christ's sake, or by way of a minced oath, e.g. cor blimey (from God blind me).