Related Clues:

• Serious
• Resolute
• Wedding ___
• 'I'll never do it again,' e.g.
• Dedicated
• Take an oath
• See 35-Down
• Deeply felt
• Zealous
• From the heart
• Give one's word
• Solemn promise
• 'I shall return,' e.g.
• Resolve
• Altar declaration