Definition
An unfashionable, quirky, socially awkward person—often said affectionately; endearingly dorky or goofy.
Examples
"He’s a bit of a dag, but everyone loves his goofy jokes at the barbie."
"Don’t mind her mismatched socks—she’s such a dag and proud of it."
"Oi, you dag, get up and show us those ridiculous dance moves again!"