Chiriwillo is used not only in Monterrey or NL state but along the north of Mexico to call the people who came from center or south of mexico. In first place from Veracruz, San Luis who are closer to the north and invades the principal cities like Mty or Saltillo etc, also from Cdmx, Oaxaca, Chiapas, Guerrero etc, all center and south of Mex
Synonyms of chiriguillo are sureños guachos centroamericanos
Used in US as well
"people from center, south of mexico"