Related Clues:

• Court smash
• Really high heel
• Volleyball coup
• Long sharp-pointed implement
• See 21 Down
• Abrupt rise
• Temporary increase
• Abrupt increase
• Piton, for one
• An ear for future agenda?
• Impale small fish
• Rail nail
• With 17-Across, 'Do the Right Thing' director
• Volleyball manoeuvre
• Huge nail