Taking an oath is a solemn declaration made by an individual, usually in a court of law, to tell the truth or to affirm a PROMISE. It is often done by swearing on a religious text or other sacred object. The five words used in the crossword puzzle to describe this concept are 'SWEAR, ' 'VOW, ' 'PLEDGE, ' 'ATTEST, ' and 'PROMISE.' To SWEAR is to make a solemn PROMISE or statement, while to VOW is to make a solemn PROMISE or commitment. To PLEDGE is to make a solemn PROMISE or commitment to do something, while to ATTEST is to provide evidence or testimony to support a claim. Finally, to PROMISE is to make a commitment to do something.