When your nan gets a cock sewed on to her.
Man, your nan has a big bulge! does she use a cushion for her fanny pad? No, she has no fanny, she's a granny-tranny!
by Bill the Fish August 13, 2006
Old Men(perferably over 50) engaged in sexual activity dressed up as Old Lady's
I was totally into that old lady till I found out she was a granny tranny
by Surg May 31, 2006
A transmission with a low gear (granny gear), usually used on trucks and other towing vehicles, to make it easy to take off on a hill with a heavy load.
This truck has a granny tranny so it's easy to learn how to drive stick shift with it.
by Eaglescout1984 January 14, 2009
A transvestite who is old enough to have or has grandchildren
Mommy says that grandma is the Granny Tranny
by Fantabuloustasticness February 26, 2015
an old man who in his photo or in person appears to be female, and folks who don't know the subject cannot determine his gender.
Dude, when I saw your photo online I thought you were a woman!!! You granny tranny!!!
by dusano December 10, 2008