Verb. The act of cheering for a team while on the wagon. A common variation of Steaming the Wagon is steam it.
The Padres need our help, they need more guys steaming the wagon.

We steamed the wagon hard and the Colts won a close one.

..as the Browns begin to lose...
Fan #1: The Browns wagon is losing steam!
Fan #2: Steam the wagon!!!
by Milt Deezy May 10, 2007
Get the Steaming the wagon mug.