A cheerleader is one of the people who leads the crowd in cheering at a large public event, especially a sports event.
2. countable noun
If you say that someone is a cheerleader for a particular cause or an individual politician, you mean that they are one of the chief supporters of this cause or politician and work hard to raise support for them.
He is a bullish cheerleader for art investment.
cheerleader in British English
(ˈtʃɪəˌliːdə)
noun
1.
a person who leads a crowd in formal cheers, esp at sports events
2.
a vocal supporter of a particular cause
a cheerleader for children's rights
cheerleader in American English
(ˈtʃɪrˌlidər)
US
noun
1.
a person who leads others in cheering for a team, as at football games
2.
a person who enthusiastically promotes or supports a cause