As a fashion movement this has been around for a couple of years, but Scott Morrison has made it mainstream in Australia this year. The essence of dadcore is comfort and a total lack of interest in style. Basic items are the baseball cap and the puffer jacket.
Dadcore fashion is combined with the dadbod, defined in the Macquarie Dictionary as:
noun Colloquial the physique characteristic of a middle-aged man who combines a no-exercise regime with a comfortable lifestyle and, in consequence, has a tendency towards being overweight, but who is, nonetheless, comfortable with his body image.
Apparently the trick is to buy clothes that don’t fit you terribly well, usually because they are too big but mostly because you just grabbed the first thing off the rack that took your eye.