faltas: offenses, sins.

faltaba: he lacked. Past of verb faltar

falten: they lack

fiera: beast

fierro: correct spelling hierro : iron

flojos: weak men

frontera: border . Martín Fierro is in the border between "christians" and indians. In times of Marín Fierro indians on the other side were pampas, they gave the name to the whole region. After their defeat and absorption came indians mapuches from Chile, who used to steal cattle and horses to be sold in the other side of Andes