Solemn words can refer to a variety of things, such as an OATH or a solemn promise. The crossword solutions for the term 'solemn words' are 'OATH' (4 letters) and 'OATHS' (5 letters). An OATH is a solemn promise or statement of truth made in a formal setting, often with religious connotations. OATHS are usually made in a court of law or in a religious ceremony. OATHS are also commonly used in marriage ceremonies and other important life events.