Related Clues:

• Nimble-minded
• Sting some
• Shiny
• Keen-witted
• Mensa-eligible
• Mentally blessed
• Word that can precede the last word of 17-, 24-, 48- and 58-Across
• Ingenious
• Like a brainiac
• Like most fast sudoku solvers
• At the head of one's class
• Sting a bit
• Snazzy
• Of high intelligence
• Shoe phone user