From Longman Dictionary of Contemporary Englishoathoath /əʊθ $ oʊθ/ ●○○ noun (plural oaths /əʊðz $ oʊðz/) [countable] 1 PROMISEa formal and very serious promiseoath of loyalty/allegiance/obedience etc an oath of allegiance to the Queenswear/take an oath Servicemen have to swear an oath of loyalty to their country. The president took the oath of office (=made the official public promises that every president makes when starting their job). She could not break her oath.2 lawSCT a formal promise to tell the truth in a court of lawon/under oath The evidence was given under oath. Witnesses are required to take the oath (=make this promise).3 SWEAR written an offensive word or phrase that expresses anger, surprise, shock etc He was shouting out oaths as they led him away.COLLOCATIONSverbsswear/take an oathAs children, they took an oath of friendship.violate/break an oath (=do something you promised not to do)I do not expect you to violate your oath.be bound by an oath (=have sworn an oath)These chiefs were bound to him by oaths of loyalty.phrasesan oath of loyalty/allegiance/obedienceThey swore an oath of allegiance to the crown.an oath of secrecyAnyone who joined had to swear an oath of secrecy.the oath of office (=the oath a government worker swears to do a job honestly and well)ADJECTIVES/NOUN + oath a solemn oath (=a very serious oath)He swore a solemn oath never to tell.a sacred oath (=one you swear by God)Stephen swore a sacred oath to recognise Matilda as Queen.the presidential oath (=sworn by a new president)the oldest person ever to take the presidential oath for the first timethe coronation oath (=sworn by a king or queen when they are crowned)
Examples from the Corpus
oath• Adams was elected to the British Parliament, but refused to swear an oath to the English Queen.• Public officials must take an oath to support the U.S. Constitution.• He shouted oaths and curses as they took him away.• The president takes the oath of office in a public ceremony.• He admitted that he had lied under oath.take the oath• The first thing you will do as a witness in court is to take the oath.From Longman Business Dictionaryoathoath /əʊθoʊθ/ noun [countable]1a formal promise to do somethingThe president has taken an oath to support and defend the Constitution.The new president will take the oath of office next week.2be under oath (also be on oath British English)LAW to have made a formal promise to tell the truth in a court of lawThe defendant acknowledged that he lied under oath.The witnesses should be examined on oath.3take the oath to make a formal promise to tell the truth in a court of lawOrigin oath Old English ath 