Related Clues:

• Fanatical enthusiast
• "Go, team!" screamer
• Ventilation device
• Word before club or mail
• Stalwart supporter
• Booster at the ballfield
• Big admirer
• Extreme enthusiast
• Completely biased
• Word on a picket sign, perhaps
• Season box holder, e.g.
• Cheering crowd member
• Fervent sort
• Not equitable
• Ceiling feature, perhaps