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knowing; being aware (of)
(an) acquaintance
ご存知ぞんじのように明日あすは祝日しゅくじつです。
As you know, tomorrow is a holiday.
もうご存知ぞんじかもしれませんが。
You may already know this, but...
ご存知ぞんじでしたら教えおしえてください。
If you know, please tell me.