paunch buns backside nates tail end arse haunch abdomen stomach keister rump midriff articulatio humeri side waistline body part hip cheek hindquarters loins tush middle ass seat bottom rear spare tire midsection behind love handle shoulder body butt tail venter fundament shoulder joint dorsum thorax prat serratus muscles posterior rear end derriere can diaphragm serratus waist back trunk belly stern chest physical structure bum tooshie buttocks buttock fanny hind end organic structure pectus