Related Clues:

• 'That's a good one!'
• ''Eureka!'' relative
• 'You can't fool me!'
• ''Funny!''
• "Well, lookie here!"
• 'Well, lookie here!'
• 'That's rich!'
• "I get it, but ..."
• Gag response
• Sounds of hearty laughter
• "And what have we here?"
• "Now I understand!"
• LOL, out loud
• 'LOL!'
• Discovery call