Related Clues:

• Visible part of an iceberg
• Something helpful
• About 15%, usually
• Service reward
• ''Lucky Lady in the fifth,'' e.g.
• Slight taste
• Cash on the table
• Jar drop-in
• Waiting bonus
• What to do to hats and waiters
• Fall, with ''over''
• Dinner charge-slip line
• Waiter's bonus
• Helpful hint
• Good thing that comes to those who wait?