Dude is an old term, recognized by multiple generations although potentially with slightly different meanings. From the 1870s to the 1960s, dude primarily meant a person who dressed in an extremely fashion-forward manner (a dandy) or a citified person who was visiting a rural location but stuck out (a city slicker). In the 1960s, dude evolved to mean any male person, a meaning that slipped into mainstream American slang in the 1970s. Current slang retains at least some use of all three of these common meanings.