腹ふく背はい

noun, noun which may take the genitive case particle 'no'

back and front; opposite sides

Literary term for the front and back of something, or metaphorically for opposing positions or feelings. The gloss 'opposition in the heart' suggests an internal conflict or duality, but this is a rare, classical usage.

• 「腹ふく背はい」は、文も字じ通どおり腹はらと背せ、つまり前まえと後うしろを指さす古ふるい表ひょう現げんだ。

  '腹背' is an old expression that literally means belly and back, i.e., front and back.