buttocks
noun
either of the two round fleshy parts of the human body that form the bottom.
backside,bottom,behind,seat,rump,rear,rear end,cheeks,hindquarters,haunches,derrière,Sitzfleisch,nates,sit-upon,stern,BTM,tochus,rusty dusty,bum,botty,prat,jacksie,bahookie,butt,fanny,tush,tushie,tail,duff,buns,booty,caboose,heinie,patootie,keister,tuchis,bazoo,bippy,batty,rass,fundament,posterior,breech,arse,clunge,ass