Related Clues:

• Rooting sound
• Low, droning sound
• Cheerleader's word
• Shout from cheerleaders
• Encouraging sound
• A bit of cheer?
• Syllable from the stands
• Spin like a top
• Bit of motivational speech
• Yay's college cousin
• Sing with one's mouth shut
• Run like an engine
• Bravo!
• Amp problem
• When doubled, enthusiastic