Related Clues:

• Riddle or puzzle
• Difficult puzzle
• See 1 Across
• Sticky problem
• Puzzling question
• Rebus, e.g.
• It's puzzling
• ''Cheese'' sayer
• Confusing question
• One in a pic
• Challenging puzzle
• Tough riddle
• It's a mystery
• Inscrutable sort
• Puzzle or fashion model