Exclamation, marking something perceived to be not worthy, usually mistaken to be understood as such. Literally it comes from the word "minchia" that means "cock" in Sicilian and Calabrian dialect (even if well understood and partially used in the rest of Italy, especially in the South and in the city of Milan) and "Zio" that means "homie" or "brother".
"Minchia zio, hai rotto lo zoca!"