Definition from Wiktionary, the free dictionary
pachuco (plural pachucos)
- A Mexican-American, especially a juvenile delinquent in the Los Angeles area.
- 1998. They asked him if he was a pachuco. He said all the pachucos he knew of lived in El Paso. He told em he didn’t know any Mexican pachucos. — Cormac McCarthy, Cities of the Plain
- (Costa Rica) uneducated person from the city who uses city slang