an enthusiastic and vocal supporter
"he has become a cheerleader for therapeutic cloning"
someone who leads the cheers by spectators at a sporting event
"The energetic cheerleader led the team to victory as she directed the crowd's loud chants during the final minutes of the game."
A person, usually a young, attractive female, who encourages applause and cheers at a sports event, and wearing a specially-designed uniform in the official colors of the team he/she cheers for.
"The enthusiastic cheerleader bounced on her toes while waving pom-poms to rally the home team during halftime."
In plain English: A cheerleader is someone who wears special clothes and leads their team with loud cheers to help them win games.
"The enthusiastic cheerleader jumped up and down to hype up her team before the big game."
Usage: A cheerleader is typically a member of an organized group that leads spectators in cheering for their team. The term can also be used metaphorically to describe someone who enthusiastically supports or promotes something.
The word cheerleader is a straightforward combination of "cheer" and "leader." It was first used to describe someone who leads the crowd in cheering at sporting events.