Showing off a new (or "new to you") vehicle by driving it around the block (neighborhood/park/lot) continuously. It is a shortened form of "grandstanding." Term is typically usually used in the Southeast by adults who grew up in the 80's.
Man, he been granding his semi-new BMW all afternoon.
by esquirej October 14, 2009
The act of doing completely random, strange, and weird things in public
Laughing randomly out loud for no reason while walking alone in public -GRANDing
by @grandICONiac August 07, 2011