背脊

背脊	bèi jǐ	the back of the human body
背	bēi	variant of 背
背	bēi	to carry on one's back / (fig.) to bear; to shoulder (a burden, blame etc)
背	bèi	the back of a body or object / to turn one's back / to hide something from / to learn by heart / to recite from memory / (slang) unlucky / hard of hearing
脊	jǐ	(bound form) spine; backbone / (bound form) ridge