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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
連絡の行違いで約束の場所に行けなかった。
Due to a miscommunication, I could not get to the meeting place.
手紙の行違いが原因で誤解が生じた。
A misunderstanding arose because the letters crossed in transit.
双方の認識に行違いがあったことが後で分かった。
It was later discovered that there was a discrepancy in both sides' understanding.