Related Clues:

• Lacking effervescence
• Place to stay in London
• Tire trouble
• Driver's headache
• Lacking pep
• Lacking carbonation
• Sharp's counterpart
• Reason to pull over
• *See 61-Across
• Toneless
• Cousin of a moccasin
• Dull and lifeless
• Sharp's opposite
• Like plains
• Opposite of sharp