Rah-rahing is a colloquial term used to describe enthusiastic and energetic cheering or supporting. It's often associated with sports events, rallies, and other public gatherings where people come together to motivate one another. There are several synonyms for rah-rahing that can be used to convey this same sense of excitement and enthusiasm. These include cheering, applauding, chanting, rooting, rallying, and hollering. Each of these words carries a slightly different connotation, but all can be used to describe the act of motivating and encouraging others to do their best and keep their spirits high.