sitzfleisch

 
Pronunciation: /ˈzɪtsflʌɪʃ/

noun

[mass noun] informal, chiefly US
  • a person’s buttocks: the bedspring tattooed waffles all over my Sitzfleisch
  • power to endure or to persevere in an activity; stamina: I was given tasks which required lots of Sitzfleisch, but didn’t offer much excitement

Origin:

from German, from sitzen 'sit' + Fleisch 'flesh'