Answer: RALLIER

AnswerCrossword Clue
RALLIERRabble rouser.
RALLIERChaffer.
RALLIERTennis player, at times
RALLIERCheerleader, at times
RALLIERPregame cheerleader
RALLIERAthlete with a second wind, perhaps
rallierone who rallies (to call together for a common purpose)