noun
back-to-back; facing opposite directions
Describes a physical arrangement where two people or things are positioned with their backs touching or facing away from each other.
二人は背中合わせに座って本を読んでいた。
The two sat back-to-back reading books.
この部屋は隣の部屋
This room is back-to-back with the next room.
noun
two sides of the same coin; inextricably linked
Metaphorical use, often implying that two things are inseparable, especially when one is dangerous or undesirable. Commonly used in phrases like 背中合わせの関係.
自由と責任は背中合わせだ。
Freedom and responsibility are two sides of the same coin.
成功と失敗は背中合わせの関係にある。
Success and failure are inextricably linked.
noun
on bad terms; at odds
Describes a strained relationship where two people are not getting along, often with a sense of mutual avoidance or tension. Frequently used with なる or だ.
あの二人は最近背中合わせになってしまった。
Those two have recently fallen out with each other.
彼とはどうも背中合わせで、うまく話せない。
I'm on bad terms with him and can't talk properly.