naco adj. common, ordinary, plebeian, unfashionable, vulgar. (source: Double-Tongued Dictionary)
Further reading
What’s it like to hike the Pacific Crest Trail all the way from Mexico to Canada? You’ll end up with sore muscles and blisters, and great stories to tell. Along the way, you’ll also pick up some slang, like NoBo, SoBo, Yo-yo and...
The slang phrase someone ate and left no crumbs means the person did something really well. In a previous call, a listener who works in theater noted the use of ate to mean “did something well,” as in they really ate that haircut! This...
In Mexico, a very derogatory / racist reference to a poor person (invariably of Indian appearance).
it can also be used for fun, not only to offend
usu used like ‘que naco’ or ‘que naca’ for a girl.