A grannyped is another word for "mobility vehicle". Mobility vehicles are small electric powered carts, usually with variable speed, indicators, reverse mode and a front loaded basket.
They are driven by either elderly folk, hense the name, or by Obese people who are to lazy to walk and loose some weight.
1. Dude, Jon got a grannyped and he's gonna pimp that sh*t!
2. Man, look at that lovely old couple, racing through the park knocking people down on their grannypeds.
3. When I'm old, I'ma score me a free grannyped.
4. I wish that fat chick would stop whoring that grannyped and let someone who really needs it use it.