Related Clues:

• Imperfection
• Sonar signal
• Needle
• Drawback
• Flub
• Submarine, on sonar
• What's holding things up
• Boo-boo
• Irk
• It's a reel problem
• Blunder
• Radar signal
• It may be fatal
• Slowdown
• One 'E' on a scoreboard