Mexican slang for "man"... there is some kind of respect implicit on this word to the guy referred as vato. Vato is a guy who means business.
The instance Bato instead of Vato should be more appropiate as it sounds on
the streets. But grammatically, both words are correct because this word hasn't been ruled by any Language academy so far.
Vato is not the same as güey. Güey does not implies respect. Güey is more alike to be pejorative or familiar depending the
way it is applied.
Fuí con este vato y me dijo que
tu ranfla ya no sirve ése...
Que pasó vato, hace
un buen que no te wachabamos por acá
en el cantón...
Saludos desde Juaritos Raza!!