Related Clues:

• Zebra
• Make some calls
• Allen Iverson, e.g.
• One may use hand signals
• One who cries foul?
• Ring leader?
• Gridiron official, for short
• Penalty declarer
• Blind official, in stereotypes
• Plate cleaner
• Striped whistle-blower
• Bomb part
• Ump's relative
• NBA official
• Referee, slangily