Related Clues:

• At-a-loss utterance
• Muser's sound
• 'Let me think...'
• 'Let's see now ...'
• End of the word ladder
• Start of a response to a brainteaser
• 'I'm thinking...'
• "I'm thinking..."
• 'Let me think about that...'
• Not down with anything
• "Things that Make You Go ___"
• It might get pumped
• "Good question . . ."
• With 38-Across, desiring happiness for someone
• ''Now that you mention it . . .''