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crossing without meeting (e.g. letters in the post, people on the road); going astray
difference of opinion; misunderstanding; estrangement; disagreement
行き違いでお互いに会えなかった。
We missed each other and couldn't meet.
行き違いがあったようで申し訳ない。
I'm sorry there seems to have been a misunderstanding.
手紙やメールの行き違いが大きな混乱を招いた。
The crossed letters caused confusion.