Related Clues:

• Pro Bowl official
• Baseball : ump :: football : __
• Judge in a dispute
• Make a traveling call, perhaps
• Whistle blower on a basketball court
• Decide who is out of bounds
• Red card issuer, for short
• Union grievance figure
• Ring official, for short
• Whistleblower (abbr)
• Person keeping track of progress, familiarly
• Beef inspector?
• World Cup official
• Call, as a game, briefly
• One who settles disputes