In principle it is a diminutive of compadre; but in Rosario and in the Río de la Plata (Argentina and Uruguay) it was a social type until well into the twentieth century. Let's remember that "compadre" was an affectionate and respectful way of being called among slum porteños, usually thugs or handsome, and that ended up almost as a generic name. The 'compadrito' was a derogatory nickname to those who were not from Buenos Aires imitated the handsome porteño, but in its worst characteristics; he was the commonly called "badly entertained gaucho" who lived or worked in the city, who ended his nights drunk and provoked knife fights. As a discriminatory form he came to name the porteño who lived in the suburbs because his economic condition could not afford to pay for a piece in the center. Over time it became synonymous with malevolent, and even took the nickname with pride.
In Argentina and Uruguay, modest person who lived on the outskirts of the city. In Colombia diminutive of compadre and name of a very popular and tropical song, very old. It was performed by the Rufo Garrido Orchestra. A few years ago it was again popularized by Moses Angulo. In Peru the stage name of Willy Ancco, a singer of danceable popular music.
