rooter

When Meek, a Mercer Island High School grad, signed with the Huskies, his grandfather became the team’s most avid rooter.

From Seattle Times ● Apr. 8, 2022

But even a rabid rooter like this reviewer did not know about “the Curse of Chico Ruiz,” an undistinguished infielder for the Cincinnati Reds who haunted the Philadelphia Phillies.

From Washington Post ● Sep. 17, 2020

I have been a USC rooter for 80 or more years and will continue to be, come what may.

From Los Angeles Times ● Jan. 3, 2020

Although I am the opposite of a Yankees rooter, I respect their rich history enough to have read dozens of books about their unsurpassed glory.

From Forbes ● Jun. 29, 2015

The "rooter," a good-looking young fellow with a Reed button and three or four gaudy badges decking his crash coat, nodded and tapped his temple furtively, still retaining his expression of radiant good-nature.

From Stories That End Well An Adventure in Altruria——Through the Terrors of the Law——The Real Thing——The Old Partisan——Max—Or His Picture——The Stout Miss Hopkins' Bicycle——The Spellbinder——The Object of the Federation——The Little Lonely Girl——The Hero of Company G——A Miracle Play by Octave Thanet