Top definition
1. The slang term for a penis longer than 8 1/2 inches.
2. A penis which has a unique maneuverability, almost a mind of its own.
3. A snake disguised as a penis.
Samir: Jeez, look at his Fierro!
James: I know, i can see it through his jeans!

Tony: Did you see how i used my Fierro?
Kevin: Yeah, it was a very convincing puppet!
by Chris Gutes August 08, 2012
Happy St. Patties Day!
Fierro is actually Italian for strong fire. And its an Italian mafia family from Sicily, not Mexico.
That Fierro is a ginnie
by Gambini May 15, 2008
Happy St. Patties Day!
Strong Mexican mafia family, construction company, Yard work, and nucular powerplant owner
by Lindz G January 08, 2008
Happy St. Patties Day!
A male person who performs the act of ass eating.
Person 1: Look its andrew.
Person 2: I don't like him! He's a fierro
Person 1: omg really that's disgusting.
by mawuto April 28, 2014
Happy St. Patties Day!