Related Clues:

• Words of comprehension
• 'Uh-huh'
• Understanding words
• 'Gotcha!'
• Words of understanding
• Psychiatrist's response
• Words of enlightenment
• 'Now it's clear!'
• 'Oh, right!'
• See 20-Across
• 'Aha!'
• 'Ah!'
• 'Understand?'
• Expression of understanding
• 'Clear as day'