Related Clues:

• 'Haven't a clue!'
• 'I have no idea'
• 'Dunno'
• Shrugger's word
• "Beats me"
• "Who knows?"
• [   ]
• 'No clue'
• Comment made with a shrug
• Not the faintest idea
• ''Beats me!''
• 'I haven't the foggiest'
• "Beats me!"
• 'Ya got me'
• How to interpret 20-, 38-, and 56-Across