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to lose sight of (one's companions); to stray from
to miss (one's chance to ...)
人混みで友達とはぐれてしまった。
I got separated from my friend in the crowd.
群れからはぐれた子鹿を保護した。
A fawn that had strayed from its herd was rescued.
旅行中に家族とはぐれて焦った。
I panicked when I got separated from my family during the trip.