My understanding is that booty means buttocks , as explained at dictionary.
The OED entry for boot is "3 British An enclosed space at the back of a car for carrying luggage or other goods.
The OED suggests that, in this sense, booty might be a variant of botty , which in turn is a reduced form of bottom.
Subscribe to RSS
A related term is "dicky" which the OED states is "2 dated, chiefly British A folding outside seat at the back of a vehicle.
Description: Community working group updates: February If this is the case, we have to factor in the fact that the word in Jamaican creole is "batty".