IPA: /ˈtʃɪərə/
KK: /ˈtʃɪrər/
A person who supports or encourages others, often by shouting or clapping, especially at events like sports games.
The cheerer led the crowd in chants to motivate the team.
Cheerer → It is formed from "cheer" (from Old French *chere*, meaning face or expression, which evolved to mean a state of happiness or encouragement) and "-er" (meaning a person who). A cheerer is a person who expresses happiness or encouragement.
Think of someone who brings a happy 'face' ('cheer') and is a 'person' ('-er') who encourages others.