The resurgence of popularity in old-school men's grooming products, like straight-razors and shaving brushes and soap, dress attire, and cocktails. Made popular by shows like Mad Men. Differs from "metro" in that it is a more gentlemanly way for a guy to spend time maintaining his appearance. It emphasizes the notion of the "classic gentlemen".
"Hey Joe, did you just get a haircut?"
"Yeah man, I went to the barber shop for a cut and straight razor shave. I'm going retro metro."
Girl 1: "See that guy wearing the three piece suit and drinking a vodka gimlet?"
Girl 2: "The one with the fedora?"
Girl 1: "Yeah, he's hot - totally retro metro."