verb: to sneak up behind someone, grab their underpants, and yank them forcefully upwards causing their underpants to get jammed up way deep in their butt crack.
dude, did you see what happened to that new fat kid on the playground? He got a grundy so hard it ripped the elastic off his nuthuggers!!!
A state of being, that is defined as one being, "Grundy". An adjective denoting a person, person's actions, or state of being distinguished as anything gnarly, without the positive attributes. Grubby, sludgy, smelly, rotten, vile, dishonest or scheming. Shenanigans, outlandish tom foolery and definitely not cool or admirable. In the hood, this can be known as "greezy".
You mean Daryl? That dude is one grundy son of a bitch. He smells like he rides a horse to work and steals everyone's tools.