Answer: Well Dressed Men

Ask a modern American-English speaker to pin down where “dude” originated from and they’ll likely guess late 20th century Californian surfer culture. Not a bad guess, but a solid century too late.

The word first entered the American-English lexicon in the 1870s and referred to men that dressed very fashionably (with a secondary use to refer to well-dressed urban men who were visiting rural areas and stuck out, what we would now call “city slickers”). That usage stuck until, in the 1960s in surfer culture, the term dude became synonymous with “guy” but by the 1970s had become unisex in usage.

Now when someone yells, “That dude is trying to break into your apartment!” they most certainly do not mean, “That very well dressed gentleman.”