“Boludo” and “pelotudo” are bad words used in Argentina specifically to mean “stupid”. But where do they come from?
In the Wars of Independence, Argentine gauchos fought against the Spanish army. They fought against disciplined men who prepared themselves in the best military academies, armed with firearms, artillery, armor, cavalry, the best steel, etc.
The Argentines only had balls, big stones with a furrow where they tied and knifes. Few had firearms.
So, what was the technique to oppose such a war machine as the one the royalists brought? The gauchos were formed in three rows: the first was that of the PELOTUDOS, who carried the balls (Pelotas) of large stones tied with a touch. The second was that of the LANCEROS, with knifes, and the third, the BOLUDOS with their balls (bolas).
When the Spaniards come with their cavalry, the PELOTUDOS, displaying an admirable courage beat the horses on their chests. In this way, they rolled and dismounted the rider and caused the fall of those who came back. The LANCEROS took advantage of this circumstance to use their knifes. And finally the BOLUDOS attacked with their balls.
In the year 1890, a Deputy of the Nation alluded to what today we would call stupid, saying that “it was not necessary to be PELOTUDO”, in reference to that one did not have to go to the front and get himself killed. The expression was similar to “you do not have to be stupid”.
BOLUDO started to be used with the same sense.
In the last two decades, young people interspersed every two or three words a BOLUDO, sometimes for nothing, sometimes by response or sometimes instead of saying “beloved”. That is to say, that it is a term of multiple uses that does not have the original sense and that in fact, we do not know why we say it.