I love it when fashion comes up with new slang that quickly spreads around the globe and I'm hoping this one is a sure thing.
I give you... the Fashlete! courtesy of Stylesightings
It's a slight variation of business on the top party on the bottom. It could also be considered a version of high/low dressing. Instead of just mixing expensive pieces with H&M finds you're also contrasting more formal attire (cashmere sweaters, leather jackets, clean sneakers) with pajamas basically. I love the whole approachable vibe it gives off.
One of the keys to great style, I think, is to always have something in your look that is slightly... off. Call it "one of these things is not like the other". Which one is it? Can you tell? And you shouldn't really be able to. Wearing a full on suit? Pair it with sneakers. Sweatpants and a hoodie? Throw on a sport coat. Nothing that's newer than 5 years? Whip out that Rolex. People will think you're an internet billionaire. It'll be fun.
For reference, the female version...