The ability to have swag while smoking weed (Taking huge rips, using proper smoking etiquette, etc) and while high or, "dim" (Being chill, polite, funny, etc).
Liam: *bubble bubble bubble*
Robert: Man, that's gonna be a huge hit.
Liam: *Keeps pulling, clears the chamber, chills, exhales, then passes the bong*
Robert: Man, you've got Dim Swag.
Liam: Lol, you do too man.