back end (n)
backside (n)
rear (n)

Definition: the side of an object that is opposite its front
Example: his room was toward the rear of the hotel.

tush (n)
tooshie (n)
tail end (n)
arse (n)
ass (n)
backside (n)
behind (n)
bottom (n)
bum (n)
buns (n)
butt (n)
buttocks (n)
can (n)
derriere (n)
fanny (n)
fundament (n)
hind end (n)
hindquarters (n)
keister (n)
nates (n)
posterior (n)
prat (n)
rear (n)
rear end (n)
rump (n)
seat (n)
stern (n)
tail (n)

Definition: the fleshy part of the human body that you sit on
Example: he deserves a good kick in the butt. are you going to sit on your fanny and do nothing?.