Related Clues:

• __ lines
• Set against
• Opposing prefix
• Pro opposite
• Start for lock or knock
• Nonsupporter
• Non-supporter
• One side in a debate
• The ''other side''
• One to watch out for
• He's not for us
• Climactic start?
• "Them," with "the"
• Archrival
• Kin of contra-