Top definition
Unexpectedly getting an erection while riding a bus. Common on field trips and rides to sporting events.
"I wear compression shorts to curb bus chubs, but it doess't always work."

"I woke up with a huge bus chub just as we were pulling into the rival school"
by CharlieScott April 29, 2007
Get the mug
Get a Bus chub mug for your buddy Bob.