It means "Fire" in Espanol. On the street in the US, its come to be a term for good drugs. The band Phish released a studio album called Fuego in 2014. The title track has references to rolling in a Fuego, a car made by the French company Renault from around 1980-1994. The song lyrics include "in your Fuego we keep it rolling, rolling, rolling" Ive never spoke to the band but its pretty much talking about Molly aka Ecstasy aka MDMA and again apparently it was FIRE.
"The Molly I took at Set break was Fuego I mean it was fire"