1. a solemn promise or declaration, often invoking a divine witness, regarding one’s future action or behavior
2. a formal promise to tell the truth, especially in a court of law
Usage: legal
3. an offensive or profane word or expression used to express anger or emphasis
Usage: informal

Examples

• The new president took the oath of office on the steps of the Capitol.
• She swore an oath to protect and serve her country.
• Before testifying, witnesses must take an oath to tell the truth.
• The doctor took the Hippocratic oath when she graduated from medical school.
• He muttered an oath under his breath when he dropped his keys.
• The soldiers pledged their oath of loyalty to their commander.
• Breaking an oath was considered a serious offense in ancient times.