Cheer on
Definition 1 of 1
Pro Tip 1/3Sporting Events
Most commonly used in sports contexts to encourage athletes or teams. 
The whole stadium cheered on the marathon runners.
Pro Tip 2/3Positive Energy
Conveys enthusiasm and positive support for someone's actions or endeavors. 
She cheered on her friend as he presented his project.
Pro Tip 3/3Audience Participation
Implies active participation from the audience, not passive watching. 
The fans cheered on their team, refusing to sit down.