An Americanism for what in proper English is a "bum bag" — a pouch or other device worn around the waist by butt sluts to hold safer-sex supplies, sex toys and other paraphernalia for kinky buttsecks. The wearer is typically clad in skintight stretch clothing to showcase their assets, leaving nowhere else to store their anal lube, condoms, butt plugs, douche or enema bulbs and other supplies needed to prepare their butts for anal sex. While jogging (running around) or cycling (peddling their arses all over town) to find a mate, the savvy buttslut comes prepared by wearing this pack (usually directly over or above the trampstamp) with everything needed to savour the fruits of Sodom.
So why, then, would a bum bag be a "fanny pack"? Most likely, a few trollops are looking for a Devil's threesome which involves double penetration — one penis in the bum, another penis in the fanny at the same time. That would require extra rubbers, extra lube and presumably redundant birth control — all of which needs to be packed away in that little pouch.
by bitchuck August 31, 2024

An extremely fleshy or meaty vulva, so much so that it resembles a pair of large testicles from certain angles. This is, of course, the British English usage of fanny.
by Iggle Piggle's alcoholic broth May 1, 2021

by Djengo July 25, 2019

Let n∈R, and let θ be a random variable with XY chromosomes. The limit of θ(n) as n tends to 2 is the Fanny constant, (your) x, which also represents the global minimum of the function θ(n).
by Most iconic people at UCBM December 18, 2024

It is a name that mostly girls call other girls just to slag them off. But it doesn't have a proper meaning
by aisling delaney July 7, 2008

by Admiral7Awesome August 5, 2018

To convince somebody to reneg on a promise that they made, in similar nature to the way the character Fanny Dashwood convinced her husband John to renege on his deathbed promise to his father that he would take care of his half-sisters and their mother in the Jane Austen novel, Sense and Sensibility.
When Mary convinced her boyfriend, Dave, that he couldn't fulfill his promise to attend his friend Nick's bachelor party, she fanny dashed nick.
by Mr Cnowledge September 24, 2015
