Possible Clues:

• Gravely and sedately
• Gravely or ceremonially
• Gravely
• With seriousness
• How to swear?
• Only hugging heartless chap in formal and dignified way
• Gravely only elms decomposed
• Sly admits lemon bake is looking more than a little sad
• Common way to swear
• Like Moths to Flames "I ___ Swear"