What is Chumbo?
1.
A derogatory (mean, rude) name for a ridiculously straight man. Often associated with trailer trash, Chumbo's tend to be womanizing, beer drinking, steak eating, american football watching heterosexists (homophobics).
This term is most often used by homosexuals and bisexuals, though can be used by any straight person who doesn't fall into a ridgid steroetype.
Vin Diesel is a Chumbo
See
2.
One who acts foolish inadvertently yet believes that they appear cool.
John thinks he is a good break dancer but he is really just being a chumbo.