Related Clues:

• Set against
• Opposing prefix
• Pro opposite
• Start for lock or knock
• Nonsupporter
• Opponent in business or sports
• Frazier, to Ali
• Hold a candle to
• Non-supporter
• One side in a debate
• Compare favorably to
• The ''other side''
• One to watch out for
• He's not for us
• Climactic start?