In colloquial language it means to flee precipitously, to escape, to whistle out of a compromised situation, as our Open Dictionary tells us. Probably its origin is in the battle of Polvoraria, (later Polvorosa, toponym of this area of Castilla-León) in the year 878 between Moors and Christians in the province of Zamora near Milles de la Polvorosa at the confluence of the rivers Tera and Órbigo with the Esla. The hosts of Alfonso III the Great defeated the Muslims by making them put their feet in dust. Others say that the day of the battle was so windy that there was a lot of dust in the air.
