1. One of the most bro forms of headgear. Commonly used as a form of protection against non-chillness (or sissiness).
2. A sombrero made entirely of Natty cans, duct tape, and a sandwich made by a woman.
1. Eric: "Oh shit, brah. That cop just put his siren on! Better pull over..."
John: "Don't worry, I got this, let me put on my sombrerbro."
*cop walks up*
Cop: " Holy shit, brah! Nice sombrerbro! I'll let you guys off free this time" *Brofists*
Substantiating the widespread belief that all Mexican men are bisexual when given enough tequila, the term refers to an otherwise heterosexual mariachi performer's unexpected enthusiasm for anal penetration by another man.
Jorge was the picture of machismo until his fifth shot of Cuervo-- then it was all backseat sombrero for the rest of the night.