Related Clues:

• Brilliant or ambitious performance
• A drawback arises about most lively party in daring display
• Stephenson's cutting edge?
• Something said to require great intelligence (usually referred to in the negative)
• Display of great skill
• Something very difficult to understand (involving gravity?)
• Show of courage
• Space technology
• Brilliant and daring display
• Virtuosity
• Daring display
• It¿s not that hard perhaps getting one to moon
• Proverbial activity requiring greater intelligence?
• Boldness supporter displayed crossing a very old city
• (Not) an intellectual demand (slang)