(especially among Mexican-Americans) a teenage youth who belongs to a street gang known for its flamboyant style.
Origin: 1940–45; < American Spanish (U.S. Southwest), Mexican Spanish: probably originally a resident of El Paso, equivalent to (El) Pas(o) + -uco pejorative noun suffix, with expressive replacement of s by ch; compare Mexican Spanish pachuco worthless card hand, derivative of paso pass