Rooter/ˈruːtər/ Definition 1 of 3Pro Tip 1/3Sports Enthusiasm Often used to describe passionate support in a sports context. As a rooter, he never misses a game of his favourite team. Pro Tip 2/3Positive Connotation Implies a positive and supportive attitude, not just casual interest. She's more than a fan; she's a dedicated rooter cheering loudly at every match. Pro Tip 3/3Informal Usage Commonly used in casual conversation rather than formal writing. Everyone in town knows him as a loyal rooter of the high school basketball team.