(Australian): Underpants.
Derives from Sydney Rhyming slang, "Reg Grundies = Undies", which is a reference to that excellent Australian TV production outfit Reg Grundy, behind such televisual classics as Neighbours, Home and Away, The Sullivans, etc.
From "The 12th Man Again", wherein commentator Max "Tangles" Walker discusses the perils of prolonged bouts of commentating on international cricket competitions:
"when you're sitting around in the commentary box for this length of time, it's not unusual, really, for the old cods to maybe nod off, get a bit numb; I think the best thing to do in situations like this is to get up, stretch the old legs; maybe even try to casually slip the old hand down and, maybe, give them a bit of a rub; probably try and adjust the old reg grundies while you're down there; try and loosen them up a bit. Anything, really, to try to get the old circulation going again."
123๐ 43๐
A dirty pair of whitey tighties
Dude sniff your mom's grundies
19๐ 40๐
(Auatralian) shortened form of government regulation undies, refering to plain or uncomfortable underwear.
It was washing day so she had to wear her grundies
11๐ 18๐
A grundie is a common wedgie.
(rear, for the ladies)
10๐ 46๐
A wedgie.
We gave the stupid little freshman a wedgie after he asked us where the elevator was.
171๐ 89๐
when your underwear goes up your butt, the same as a wedgie.
Sarah has a grundie she has to pick it.
54๐ 34๐
Reference to one's huge ego. Typically paired with English/Scottish males named Joe.
"Wow! He seems a bit far up himself!"
"Yeah he is a bit of a Grundy."
11๐ 7๐