verb
to grind out, to chip away (to make a lengthy and laborious effort)
“El ministro catalán de Economía, Andreu Mas-Colell, resumió su visión del problema con este pronunciamiento: «Nosotros los catalanes hemos estado trescientos años picando piedra [se entiende que contra el Estado español]^([sic]) y lo más probable es que tengamos que seguir haciéndolo durante trescientos años más.»” — The Catalan Minister of Economy, Andreu Mas-Colell, summed up his vision of the problem with this statement: "We Catalans have spent three hundred years chipping away [it is understood that against the Spanish State]^([sic]) and most likely we will have to continue to do so for another three hundred years.”
Literally, “to chop stone”.